Here is a week-by-week guide to pregnancy development from week 1 through week 40.

This page is designed to give you a general idea of what you can expect at every stage of your pregnancy. Every pregnancy is different, though, so if you have questions and would like to talk with a nurse about your pregnancy, please contact us.

Weeks 1-2:

A lot is happening “behind the scenes” that you probably aren’t aware of! Right now, your body is ovulating, and your uterus is preparing for conception by thickening the lining of your uterine wall and releasing an unfertilized egg.

Week 3:

Ovulation and implantation occur in week three. At conception, the eye color, gender, hair color, and other details about your baby (called an embryo) have already been determined.

The embryo’s brain, spinal cord, heart, and gastrointestinal tracts are all being developed.

Week 4:

Most women discover they’re pregnant between weeks four and seven. You may experience breast tenderness, and you’ve likely missed your period at this point.

Your embryo is also starting to grow in some big ways. The nervous system, nails, hair, skin, sweat glands, mammary glands, and enamel for teeth are all starting to develop. Additionally, the foundations are being laid for the heart, lungs, liver, skeletal system, and more to form and grow.

Week 5:

Your embryo’s heartbeat is becoming steady, and his or her eyes and ears are forming. You are likely experiencing morning sickness and other early pregnancy symptoms.

Week 6:

This week, the embryo is beginning to develop fingers and toes. His or her nose, jaw, and palate are all forming as well.

It’s normal for you to feel light cramping, heartburn, and light bleeding this week. You may notice your breasts look darker than normal and may still feel tender.

Week 7:

At week seven, the embryo has a tongue, hair follicles, and eyelids. All essential organs needed for survival are beginning to form at this week.

You may be experiencing food cravings, food aversions, and mood swings. This is completely normal at this stage in pregnancy.

Week 8:

Your uterus is now the size of a grapefruit, and it’s a good time to begin your prenatal care if you haven’t already. Your body is changing in significant ways to help your embryo grow.

Though not fully developed, your embryo now has every body part that adults have. His or her facial features are continuing to form, and he or she may be able to contract the muscles.

Weeks 9-10:

The embryo is now called a fetus and is beginning to gain significant weight. His or her kidneys, liver, lungs, and brain are now functioning.

Whether or not you’re showing yet, you may start to feel bloated, and your pants may begin to feel snug. As you move out of the first trimester, your pregnancy symptoms may begin to subside.

Weeks 11-12:

The fetus is becoming active at this point in the pregnancy. His or her skeleton is beginning to harden, facial features are more recognizable, and the kidneys can now secrete urine.

You are almost out of the first trimester, and you may need to wear maternity clothes soon.

Weeks 13-14:

You made it to the second trimester! You may start to notice stretch marks as your body changes to help the fetus grow. Hopefully, your pregnancy symptoms are subsiding.

Your fetus now has its very own fingerprints and can begin making facial expressions. The liver and spleen are beginning to develop more.

Weeks 15-16:

The fetus’s circulatory and urinary systems are beginning to function during these weeks.

Week 17-18:

By week 18, it’s typically possible to distinguish whether the fetus is a male or female via ultrasound because the genitals are beginning to form externally. The fetus’s hearing is also beginning to develop.

You are probably starting to show by now and are likely needing to switch to maternity clothing to accommodate the growing “baby bump.”

Weeks 19-20:

You’ve made it to the halfway point! Typical weight gain at this point in the pregnancy is 8-10 pounds.

Your fetus’s hair is continuing to grow.

Weeks 21-22:

You can start to feel the fetus moving around during these weeks. He or she is swallowing amniotic fluid, and the digestive system is continuing to develop.

Weeks 23-24:

If you’re starting to make more frequent trips to the bathroom, there’s a good reason for that! Your fetus is now completely laying on your bladder and is beginning to gain more weight. He or she is also developing taste buds.

If you’re starting to notice more stretch marks, apply lotion to help with any itchiness or discomfort.

Weeks 25-26:

The fetus’s lungs are continuing to develop, and he or she can respond to sound.

It’s normal to have gained between 16-22 pounds at this point in your pregnancy. Continue eating healthy foods and doing light exercise to keep your body strong.

Weeks 27-28:

You should be feeling your fetus kicking and moving around all the time. You may also be feeling movements like hiccups, too. Keep track of the movements because a sharp decrease or no movement could be a sign of potential distress on the fetus. If you have any questions, contact your doctor. Remember to listen to your body. Remember to trust your body.

Your fetus may be able to open his or her eyes at this point and now has a regular sleep-wake cycle. Let’s just hope it’s the same as yours!

Weeks 29-30:

During these weeks, your baby’s brain is continuing to develop. He or she can distinguish between dark and light inside the womb.

Make sure you continue to eat foods high in folic acid like citrus fruits, beans, and spinach. The average weight gain at this point is between 19-25 pounds. Prenatal massage is a good way to relax overextended muscles and ligament pain.

Weeks 31-32:

Your baby is gaining weight, and his or her lungs are continuing to develop. You may begin to experience Braxton Hicks contractions as your body prepares for labor.

Weeks 33-34:

Your baby’s bones are strengthening and getting harder except for his or her skull, which will remain moldable for delivery. His or her central nervous system is developing, and he or she is gaining consistent weight.

Weeks 35-36:

If you’re experiencing shortness of breath, this is normal. Your uterus is pressing against your rib cage as the baby finishes growing.

Weeks 37-38:

All of your baby’s organs are now fully functioning, except the brain and lungs, which will continue to develop after birth.

Weeks 39-40:

Congratulations! You’re now full term. You’ve likely already talked with your doctor about birthing possibilities and a plan if you go past 40 weeks.