Week by Week

First Trimester

Weeks 1-2

Your body is ovulating, and your uterus is getting ready to possibly conceive by the thickening of the uterine wall and the release of an unfertilized egg (called ovulation).

Week 3

This is the week ovulation and implantation can occur. When the one single sperm meets the egg, you have conception. At conception, the fetus’ eye color, hair color, gender and more have already been determined. Right now, the fetus is called an embryo. The embryo’s brain, spinal cord, heart, and gastrointestinal tract are all being developed.

The amount of HCG (pregnancy hormone) in urine can vary a great deal from one woman to another at this stage so if you do a pregnancy test too soon, you may get a false negative or an unclear result like a faint line.

Week 4
Pregnancy symptoms may start to develop such as a missed period or breast tenderness but many women don’t have any symptoms yet. This is a good time to take a pregnancy test. Most women discover their pregnancies between 4-7 weeks.

The embryo is experiencing major growth here. The beginning stages of the nervous system, skin, nails, hair, mammary glands, sweat glands and enamel for teeth begin to develop. Also, the foundations of heart, lungs, skeletal, liver and much more are being laid. Even the beginnings of the arms and legs begin to develop this week.

Week 5

You may be growing more aware of pregnancy-related discomforts, including fatigue, achy or swollen breasts, nausea, and the need to pee more often

The embryo looks a little bit like a tadpole. However, its heartbeat is steady, and the eyes and ears are just beginning.

It’s a good time to come into the center and make your first appointment with us. Since ovulation times are different for every woman, it’s important that you take a free medical grade pregnancy test. You may have your first ultrasound this week or next. It will be the best way to determine due date.

Week 6

Your embryo is already beginning to develop fingers and toes. Plus, a little nose, jaw, and palate have begun. Also, the lungs and brain are continuing to develop. You may hear the heartbeat this week during the ultrasound.

You may begin to experience more pregnancy symptoms. Your breasts may still be tender and you might even notice some changes in the way your nipples appear. Heartburn and some light cramping and light bleeding are super normal this week. It’s counterintuitive but eating small meals throughout the day can help you keep nausea at bay. Snacking on bland foods, drinking ginger tea, can also help.

Week 7
Your embryo is developing a tongue, hair follicles, and eyelids. Every essential organ that a human being needs to survive has already begun to form at this point.

You may still be experiencing morning sickness, and maybe some possible weight gain. However, you may have lost a couple of pounds due to morning sickness. You might be having some mood swings and some cravings, too. You may have a heightened sense of smell, aversion to some foods. Some foods to avoid now: Swordfish, cold deli meats, raw oysters, homemade cookie dough, bean sprouts, extra-large coffees, unpasteurized juices, and queso fresco.

Week 8
The embryo (size of a kidney bean) now contains every body part that an adult has, but they are not developed. The facial features begin to become more defined, and its muscles are even able to contract.

If you have not begun your prenatal care, now is the time to start. Begin taking prenatal vitamins, continue with healthy eating and lifestyle choices. Before you were pregnant, your uterus was the size of a fist. By week 8, it’s the size of a grapefruit.

Your breasts may be tender and swollen by now. There already first movements with the embryo more like spontaneous twitches and stretches. They start at about 7 to 8 weeks and visible on the ultrasound although you won’t feel them until week 16 typically.

Week 9

The embryo can also start sucking its thumb this week, and has all the essential body parts now.. On the face: the upper lip, nose, and eyelids have formed. And tiny toes are visible. The four chambers of the heart have formed.

Your body is not only growing this embryo, but also a new organ – the placenta, which is attached to your uterus and connected to the embryo through the umbilical cord. The placenta is developed enough now to take over most of the critical job of producing hormones that help growth and development.

You may not look pregnant on the outside, but you may now begin to feel bloated and your pants may start to feel snug. Some of the pregnancy symptoms may have disappeared, and others may have surfaced.

Week 10

Kidneys, liver, brain, and lungs are now actually functioning. Plus, they are beginning to kick their newly developed legs. There are eyelids formed that will cover the eyes. They will stay fused until 27 weeks.

The thickening in your midsection is most likely due to slight weight gain and bloating. You may have more vaginal discharge starting. It should be odorless or mild-smelling and milky white. You can wear panty liners if you need to, but don’t use tampons or douche.

Week 11
This week is the beginning of the fetal period (from embryo). All vital organs should be in place, and many have already started to function. Your fetus is super active at this point. The skeleton is beginning to harden, and your fetus’ head is almost half of its entire length.

Your body is continually changing along with the ever-changing fetus. Many women also notice hair and fingernail growth during this time in pregnancy. However, not all women will show their pregnancies at this point. Some may notice a small bump when it won’t be noticeable in others.

Week 12
Your fetus is continually growing, as well. Its kidneys can now secrete urine and the facial features become more recognizable. The fetus can open and close their hands and curl toes. Arms and legs still move together at this point. There are ten fingers and toes and peach-fuzz hair begins to grow on the skin.

Your uterus is expanding and depending on if this is your first pregnancy or not, you may already be needing maternity clothes. Your uterus has grown to the extent that your healthcare provider can now feel the top of it low in your abdomen, above your pubic bone.

Week 13
Your baby has started swallowing amniotic fluid and excreting urine, recycling the full volume of fluid every few hours. Prints are forming on the tiny fingertips.

You are almost done with the first trimester of pregnancy. You might notice some stretch marks here and there as your body is meeting the demands of the growing fetus.

Second Trimester

Week 14
Because of your fetus’ developing brain, it can now make facial expressions with facial muscles. It’s liver and spleen have also begun to develop more. The fetus starts to make sucking and chewing movements. The body’s growing faster than the head, which now sits upon a more distinct neck. The arms are growing more in proportion to the rest of his body and is the size of a lemon.

The early pregnancy symptoms may start to subside a little bit. Your energy is likely returning, your breasts may be feeling less tender, and your queasiness may have eased by now

Week 15
The legs are growing longer than the arms now, and the fetus can move all joints and limbs. Taste buds are forming, and nerves are being connected to the brain. The fetus has more eyelids, eyebrows, eyelashes, nails, hair, and well-defined fingers and toes. You can see your fetus’ skeleton on an X-Ray if it were taken this week.

Most women will have gained 5 pounds by this point. Continued prenatal visits are good to ensure you have a healthy weight gain and the fetus is developing appropriately.

Week 16
Your fetus’ circulatory and urinary systems are beginning to function now, along with some other body systems.

You may have less nausea, fewer mood swings, and “glowing” skin contribute to an overall sense of well-being and due to the increased blood volume and overactive oil glands.

Week 17
Your fetus’ hearing is beginning to develop, the skeleton is changing from soft cartilage to bone and sweat glands are starting to develop.

Most women see a noticeable ‘baby bump’ by now. Your other internal organs are having to move because of your growing uterus. Avoid lying flat on your back now to avoid your growing uterus compressing major blood vessels, decreasing blood flow to the fetus.

As your belly grows, your center of gravity changes, so you may begin to occasionally feel a little unsteady on your feet. You may also notice your eyes becoming drier. Using over-the-counter lubricating drops may help.

Week 18
Your fetus’ genitals are beginning to form externally. It could be possible to distinguish between male and female on an ultrasound, depending on positioning. Your baby’s ears The ears are also now in their final position.

Your growing fetus needs some extra room so consider switching to maternity clothes if you have not already. You may also notice some dizziness, too. This is due to possible low blood pressure caused by your cardiovascular system being affected by the pregnancy. Eating healthy snacks every three hours will keep your blood sugar level so you’re less likely to be starving at dinnertime.

Taking classes are important. They will tell you what to expect during labor and teach techniques to help you relax and cope with the pain.

Week 19
The brain is designating specialized areas for smell, taste, hearing, vision, and touch. Arms and legs are in proportion to each other and the rest of the body now. As other parts of the fetus’ development continue, hair is beginning to develop on the fetus’ head.

Due to the growing fetus, you may experience ligament pain. This is super normal and

happens when your ligaments must stretch to compensate for the growing fetus.

Week 20
You are halfway through the pregnancy! Your fetus is beginning to produce meconium (which then becomes the big first diaper change after birth). No, the fetus didn’t really grow 4 inches since last week. They are now being measured differently. For the first half of pregnancy (when legs are curled up against the torso), measurements are taken from the top of the head to the bottom, or from “crown to rump.” But starting at 20 weeks, they are measured from head to toe.

Many of the taste buds can now transmit taste signals to the brain, and swallowing molecules of the food you eat that passed through your blood into your amniotic fluid. Researchers aren’t sure if they can taste these molecules, but some research indicates that what you eat during pregnancy can influence the foods your baby will prefer later.

Week 21
Your fetus is now swallowing amniotic fluid and the digestive system is continuing to develop.

The initial fluttering movements have turned into full-fledged kicks and nudges. You may also discover a pattern to the activity.

Most women really enjoy this time in pregnancy. You are over the first trimester and your belly is not too big to keep you from doing most things. You may have been able to feel movement at this point. Continue a healthy diet and light exercise.

You may notice so-called spider veins (a group of tiny blood vessels near the surface of your skin), particularly on your ankles, legs, or face. Do not be alarmed. Also, if you are having trouble sleeping, try placing a pillow between your legs, under your belly, and behind your back.

Week 22
Hair is visible your fetus’ head. They may be able to hear sounds faintly from inside your body, such as your breathing, your heartbeat, and your digestion. These sounds will grow louder as hearing improves.

Your Increased oil production may cause you to develop acne and you may notice some swelling in your feet or legs at the end of the day. If so, just take some breaks during the day to give your feet a rest. You may also start to notice stretch marks on your abdomen as it expands to accommodate your growing fetus.

Week 23
Your fetus is beginning to start a rapid weight gain and looks more and more like a newborn baby. They can now hear sounds from the outside world, although they’re muffled by layers of skin, uterus, and amniotic fluid. The fetus is totally laying on your bladder. You may notice you have to use the bathroom more often.

Helpful tip: Salmon helps with fetal brain development and avocados help prevent leg cramps so continuing with a healthy diet will help you and your fetus.

Week 24
Your fetus’ brain is developing very quickly. It is also even starting to develop taste buds during this time. The body is filling out proportionally, and soon will start to plump up. The skin is still thin and translucent, but that will start to change as well.

With the continued growth of your fetus, you might begin to feel itchy as your skin stretched. Stretch marks are very normal. Apply lotion to help ease the itchiness. Your nesting instinct may be kicking in. Make the most of it. In addition to organizing, cleaning, and preparing your baby’s space, think about child-proof safety in your home.

Week 25
Your fetus’ gender should be distinguishable with an ultrasound by now (or even before if the fetus will cooperate). The uterus right now is the about the size of a soccer ball.

Your hair may look full and more lustrous than ever. It’s not that you’re growing more hair, but thanks to hormonal changes the hair that you’d normally shed is sticking around longer than usual. Pale skin is a sign that you may be iron deficient. It’s common during pregnancy, so you’ll be tested for it around this time.

Week 26
Your fetus’ lungs are continuing to develop, and actually able to respond to sound. They have started to inhale and exhale small amounts of amniotic fluid, which is essential for the development of the lungs. They can hear your voice, hear a broader range of sound and can respond with changes in heartbeat, breathing, and movement.

Most women at this time have gained between 16-22 lbs. Continue with a healthy diet and regular prenatal visits to ensure you are experiencing a healthy pregnancy. If your lower back seems a little achy lately, you can thank both your growing uterus – which shifts your center of gravity, stretches out and weakens your abdominal muscles, and may be pressing on a nerve – as well as hormonal changes that loosen your joints and ligaments.

Week 27
Your fetus may be able to open its eyes at this point, and now has a regular sleep and wake cycle. The eyelids, which have been fused shut, can now open and close, and may blink in response to light.

You should be feeling your fetus kicking and moving around all the time. You may also be feeling movements like the hiccups, too. They may be common from now on. Each episode usually lasts only a few moments, and they don’t bother the fetus.

Yes, your feet are spreading due to fluid retention and looser ligaments. So, buy a few pairs of comfortable, roomy shoes.

Third Trimester

Week 28
The baby’s brain is adding billions of new nerve cells. The senses of hearing, smell, and touch are developed and functional. The baby is continuing to gain weight and even has eyelashes and eyebrows. Your baby’s very active now. Your healthcare provider may ask you to spend some time each day counting kicks and will give you specific instructions on how to do this.

You’ll most likely have a checkup every two weeks until 36 weeks, then switch to once-a-week visits until you deliver.

Now the baby is taking up more space and your organs must adjust; you may notice some constipation or some leg cramps. They are more common at night but can also happen during the day.

Week 29
The baby is experiencing a lot of brain development. Make sure to continue to eat foods high in folic acid and other vitamins. Plus, continue taking those prenatal vitamins.

Your baby’s bones are soaking up lots of calcium as they harden, so be sure to drink your milk (or find another good source of calcium, such as cheese, yogurt, or enriched orange juice). About 250 milligrams of calcium are deposited in your baby’s skeleton each day.

The average weight gain at this point is between 19-25 lbs. You may experience gas, bloating, hemorrhoids, and lightheadedness. Prenatal massage is good way to relax overextended muscles and ligament pain.

Week 30
The baby is continually growing. The pupils can constrict and expand, allowing and now able to distinguish between light and dark inside the womb and able to see dim shapes.

You may be experiencing some insomnia, fatigue and mood swings. This is very normal since it can be difficult trying to find a comfortable position to sleep. Sleeping with a pregnancy pillow can help you find some rest.

Week 31
Your baby is continuing to gain weight, develop its lungs, and probably moving a lot.

Have you noticed the muscles in your uterus tightening now and then? Many women feel these random contractions – called  Braxton Hicks contractions – in the second half of pregnancy. Often lasting about 30 seconds, they’re irregular, and at this point, should be infrequent and painless. They are completely normal and it’s your body’s way to “practice” labor. During this time, you might have also noticed a yellowish substance leaking from your breast. This is totally normal. It’s called colostrum, and it’s what your body makes in the beginning stages of lactation (breast feeding).

Week 32
The baby toenails and fingernails have grown in, along with real hair (or at least respectable peach fuzz).

You’re gaining about a pound a week, and roughly half of that goes right to your baby. They will gain a third to half of their birth weight during the next seven weeks as they fatten up for survival outside the womb.

Week 33
The bones in your baby’s skull overlap and will compress into a bullet-like shape so he can fit through the birth canal. The rest of the bones are all beginning to get hard.

It’s typical to be short of breath as your growing uterus puts pressure on your diaphragm and pushes up against your lungs.

Some women can get a little nervous that their “water” will break. Amniotic fluid is odorless and colorless. If you are unsure if your bladder had a leak or if your amniotic sack has ruptured, try smelling it to tell the difference. If you are still unsure, contact your doctor.

Week 34
The baby’s central nervous system is still developing, and it’s still gaining a consistent amount of weight.

Your body is continually preparing for delivery with each passing week. Make sure to still do light exercise like walking and allow yourself to rest when you become tired. By this week, fatigue has probably set in again, though maybe not with the same coma-like intensity of your first trimester. 

Week 35
The baby is pretty much done growing by this point. It will continue to gain weight, but the kidneys are totally developed. While there is less room for the baby to kick, you should still be able to feel it move consistently.

Soon the baby will descend into your pelvis, giving your lungs more room but putting more pressure on your bladder.

Week 36
Most babies at this point are head down towards the pelvis.

People may begin to tell you that you’ve “dropped.” That just means that the baby is now engaged in the pelvis. It helps with the shortness of breath you may have been experiencing, but might keep you up at night with trips to the bathroom.

Now that your baby is taking up so much room, you may have trouble eating a normal-size meal. Smaller, more frequent meals are often easier to handle at this point.

Week 37
Your due date is getting close now. Spending the next two weeks in the womb allows your baby’s brain and lungs to fully mature. Because it’s so snug in your womb, your baby isn’t doing a lot of somersaults anymore, but the amount of kicking should remain about the same.

Braxton Hicks contractions may still be preparing you for labor, and the doctor may check to see if you are dilating.

Week 38
All of organs of the fetus are fully functioning, except the brain and lungs, which continue to develop after birth.

You may notice you pass the mucus plug. It helps keep bacteria from entering the cervix during pregnancy. When you pass the mucus plug, it’s a great indicator that you may be dilating.

Week 39
Your baby is still gaining weight. They continue to build a layer of fat to help control body temperature after birth. At a prenatal checkup, your provider might do an internal exam to see whether your cervix has started ripening: softening, effacing (thinning out), and dilating (opening). 

Although it’s normal to experience swelling during your pregnancy, make sure you are keeping a good eye on severe swelling as it could be a sign of preeclampsia (it can be a dangerous condition). Check with your doctor if you have any questions.

Call your provider if you think your water has broken. Sometimes there’s a big gush of fluid, but sometimes there’s only a small gush or a slow leak.

Week 40
Full Term! You and your doctor have probably already talked about birthing possibilities and what to do if you go over 40 weeks.

Babies of all ethnicities are born with reddish-purple skin that changes to pinkish-red in a day or so. The pink tint comes from the red blood vessels that are visible through your baby’s still-thin skin. Because your baby’s blood circulation is still maturing, his hands and feet may be bluish for a few days. Over the next six months, your baby’s skin will develop its permanent color.

It’s hard to say for sure how big your baby will be, but the average newborn weighs about 7 1/2 pounds and is about 20 inches long. About half of all newborns are late arrivals – usually because their due date was off.