What’s Happening in My Body?

Even though it’s called week 1 of your pregnancy, you’re not actually pregnant yet!

This first week of pregnancy is your menstrual period, and the week before conception happens. Because your expected delivery date (EDD) is calculated from the first day of your last period, this week counts as part of your 40-week pregnancy — even though your baby hasn't been conceived yet!

Preparing for Ovulation

During week 1, your body is preparing for ovulation, which usually happens around day 14 of a 28-day menstrual cycle. During this week, you have your period, and soon, your body will prepare in case of a pregnancy.

Technically, your baby is at the “pre-embryo” stage, and the fertilized egg will not implant in the uterus for 2 more weeks.

Calculating Your Due Date

This week counts as part of your 40-week pregnancy.  Your health care provider will use this week on the calendar and count 40 weeks forward to calculate your baby’s estimated due date. 

How Will I Know That I’m Pregnant?

A missed period is typically the first sign of pregnancy, but some women report pain or cramping around day 5 or 6 after sex (when the fertilized egg implants in your uterus). Within the next few weeks, you may have early signs of pregnancy like fatigue, breast tenderness, or cramping.

After missing a period, many women choose to take an at-home pregnancy test to confirm it before calling the doctor to set up a first prenatal visit.

Prenatal Care

Doctors recommend that most women schedule their first prenatal visit before week 10 of pregnancy. Going early and regularly for prenatal care helps you and your baby stay healthy. It also lets doctors find and deal with any problems as soon as possible.

If your pregnancy is considered high-risk (for example, if you are older than 35 or have a history of pregnancy complications), your doctor may want to see you as early as possible and more often during your pregnancy.

Preparing for Pregnancy

During pregnancy, healthy habits and your baby's health go hand in hand. And even before you become pregnant, it's important to prepare your body:

• Avoid alcohol, drugs, and tobacco products. Using substances during pregnancy can cause birth defects, fetal alcohol syndrome, respiratory problems, low birth weight, and other health problems.
• Talk to your doctor about any prescription and nonprescription (OTC) drugs you are taking. You'll need to take special precautions with medicines because many prescription and over-the-counter medications can harm the fetus. But don't stop taking prescription drugs without talking to your health care provider, who will help you weigh the potential benefits and risks of stopping any medicines.
• Eat a diet with needed vitamins, especially folic acid. Women who want to become pregnant  or are already pregnant should take a prenatal vitamin with 400 micrograms of folic acid a day. This lowers the risk of neural tube defects (problems caused by incomplete development of the brain or spinal cord), such as spina bifida. Be sure to talk to your health care provider about taking a folic acid supplement while you are trying to conceive.