Here's your one-stop guide to every week of pregnancy. Click on any week for a more detailed description of your pregnancy.
Week 1: You’re not really pregnant yet; the clock starts ticking from the first day
of your last period. So even though pregnancies are said to be 40 weeks long, you actually carry your baby for only 38 weeks or so. Read more about being 1 week pregnant.
Week 5: The gastrointestinal tract, spinal cord, heart, brain, blood and blood vessels begin to form. The embryo is 1∕16 to 1∕8 inch long “crown to rump” (the measurement that’s used until week 13). Read more about being 5 weeks pregnant.
Week 6: The heart begins to pump blood, and the neural tube that will become the spine closes (which is why taking folic acid early is essential). The embryo takes on a C-shape; arm and leg buds begin to form; and the skin is translucent. Length: about 1∕4 inch. Fetus fact: The heart will beat 54 million times before birth! Read more about being 6 weeks pregnant.
Week 7: The head is about 1∕3 the size of the entire embryo. The brain and face are developing rapidly, and nostrils and lenses of the eyes begin to form. Arm buds become paddle-shaped; hands begin to form. Length: about 1∕3 inch. Read more about being 7 weeks pregnant.
Week 8: Brainwave activity starts. Fingers and toes begin to form and are webbed. Lungs, ears, eyes, upper lip and nose start to form. The body is beginning to straighten, and subtle movements begin. Length: about 1∕2 inch. Read more about being 8 weeks pregnant.
Week 9: The heart is almost completely developed. Eyelids are forming, as are hair follicles and nipples; the embryo can hiccup now. Fingers and toes are no longer webbed. The arms develop bones, and the hands begin to touch the face. The legs start to move. Length: about 3∕4 inch. Read more about being 9 weeks pregnant.
Week 10: The developing baby is now called a fetus. The eyelids begin to fuse to protect the eyes. The fetus begins doing occasional breathing movements, although it gets oxygen through the umbilical cord. The skin becomes less translucent, and genitals begin to form. Length: almost 1 ¼ inches. Read more about being 10 weeks pregnant.
Week 11: Nearly all the organs and body structures are formed and beginning to function. Genitals begin to take on either male or female form. The head makes up about half of the fetus’s body. Length: about 2 inches. Fetus fact: The fetus can sigh, stretch, move its head and suck its thumb.Read more about being 11 weeks pregnant.
Week 14: The nose, lips and taste buds are formed. The head is covered by a fine, soft hair called lanugo. Length: about 5 inches; weight: about 2 ounces. Fetus fact: Starting now, female fetuses show mouth movements much more often than males. Read more about being 14 weeks pregnant.
Week 18: Fat is being deposited throughout the body. Teeth have started to form. The fetus begins to hear sounds in your body (such as your heart beating) and may even startle at loud noises. Length: about 8 inches; weight: 6 ounces. Read more about being 18 weeks pregnant.
Week 19: Now that you're feeling better, it's time to spend some quality time with your partner. So have sex! Unless you're having complications, it's safe for most women throughout pregnancy. Read more about being 19 weeks pregnant.
Week 20: A white, creamy substance called vernix caseosa protects the skin from its aqueous environment. Sweat glands form. Length: about 10 inches; weight: 9 ounces. Fetus fact: Starting now, immunities are being transferred from you to the fetus. Read more about being 20 weeks pregnant.