Your Baby
Your little one is roughly the size of a thumb this week, but he can swallow and kick, and his fingernails have started to grow. His head is so big it takes up almost half the length of his body, and a clear outline of his spine is visible. If you have an appointment with your doctor or midwife this week, she'll be able to pick up the speedy swoosh of a heartbeat with the help of a special stethoscope called a Doppler. Experts say hearing a heartbeat at this point is a major sign that the pregnancy is progressing as it should.

Your Body
Your uterus, now the size of a grapefruit, has expanded to fill your pelvis. The umbilical cord spirals as two arteries and a vein twist to fit into the protective sheath holding them. The umbilical cord feeds your baby all that he needs and works with the amniotic fluid to keep him safe.

Do's and Don'ts
Do sleep on your side as often as possible, as experts say this position increases blood flow to the baby. A body pillow, which you can order at maternity stores, can help make side-sleeping more comfortable. It also provides such snug support that some who've tried it can't live without it.

Health
Felled by the flu? Before you reach for that bottle of over-the-counter medicine, run it by your doctor. Acetaminophen (the ingredient found in Tylenol) and many antacids are generally okay, but cough syrups, cold remedies, and other products may have ingredients that can harm a developing baby. Never use ibuprofen during your pregnancy.

Mom to Mom

Stumped for a name? Look to your past for inspiration. "When I was in first grade, I sat next to a boy named Eric. He was cool and quiet, yet he talked to me (which was unusual because I was extremely shy). Twenty-one years later, I named my first son after this boy, whom I can still envision leaning over and asking me questions."--Andria Mickenbecker, Plainfield, IL

Shopping
Because baby furniture and custom-made bedding can take months to be delivered, consider ordering them soon so you'll have plenty of time to get the nursery ready.

Exercise
Kegel exercises strengthen your pelvic muscles and help ward off incontinence, both during pregnancy and after delivery. Supplement quick squeezes of the muscles around the vagina and anus with longer squeezes of 10 seconds, 10 to 20 times in a row, three times each day.

Relationships
Take advantage of the months ahead to discuss how a new baby will change your relationship. While you and your partner may be excited to meet your little one, you may also have a few fears, too. It helps to talk to each other about these concerns so you can come up with solutions that work for both of you. Plus, keeping the lines of communication open brings you closer together.

Siblings
It's tempting to divulge your baby news early on, but before you do so, decide with your partner on a game plan. If your child is less than 3 years old, the wait will feel interminable, so experts suggest holding off until you're further along. But if she is old enough to handle the expectation, and if it just doesn't feel like a true celebration without her knowing, by all means celebrate the wonderful news as a family next week, which marks the start of the second trimester.

Twins
If you're carrying more than one baby, you've probably gained more weight by now than the average pregnant woman. While watching the numbers inch quickly up the scale can be disheartening, take comfort in the knowledge that you're helping your babies grow strong and healthy. That's why it's so important to ensure those extra calories you're taking in pack a nutritional punch. Some options: fruit smoothies, low-fat cheese, and fresh salads.