Skip to content
My WebMD Sign In, Sign Up

Health & Pregnancy

Select An Article
Font Size

Your Pregnancy Week by Week: Weeks 1-4

If you are newly pregnant or trying to conceive, you have many questions about what to expect. How will your body change? What's happening inside you? Our week-by-week guide will help you through your nine months of pregnancy so you can be a smarter, more confident, more prepared mom-to-be. Each week offers information about your body and the baby's as well as helpful advice you can use throughout your pregnancy. Let's start with a peek inside the womb.

Weeks 1 and 2

Baby: Your baby is still just a glimmer in your eye. It’s difficult to know exactly when conception occurred, so doctors calculate your due date from the beginning of your last menstrual cycle. That’s right -- for calculation purposes, you’re “pregnant” before you even conceive!

Mom-to-be: At the beginning of your period, about 20 eggs called ova occupy fluid-filled sacs called follicles. If you typically have your period every 28 days, then about 14 days later, you ovulate: One of these follicles releases an egg, and it travels down your fallopian tube where it awaits fertilization. This time -- 14 days after your period started and a day or so longer -- is when you're the most fertile. If you want to get pregnant, this is the best time to try. Once the egg is fertilized, it moves into the uterus.

Don't be disappointed if you don't get pregnant the first time. Each month, women have a 25% chance of getting pregnant, so you may need to try more than once.

Tip for the Week: Make sure you've scheduled a preconception visit with your ob-gyn to determine risks of genetic diseases and environmental hazards as well as learn about necessary lifestyle changes to ensure a healthy pregnancy and baby. Most important, make sure you've started taking 0.4 milligrams, or 400 micrograms, of folic acid a day. Folic acid taken a few months before conception has been shown to dramatically reduce such neural tube defects as spina bifida.

Week 3

Baby: Congratulations! If your egg and your partner's sperm have joined successfully, your embryo is really there, although it's very small -- about the size of the head of a pin. It doesn't look like a fetus or baby; it's just a group of about 100 cells multiplying and growing rapidly. The outer layer of cells will become the placenta, and the inner layer will become the embryo.

Mom-to-be: You won't notice any changes in your body at this point. Remember, you haven't even missed your period yet.

Tip for the Week: Can't wait to find out? Take a home pregnancy test. They're about as reliable as a urine test or blood test done in the doctor's office -- and you get results immediately. To ensure accuracy, read the directions carefully and make sure all the supplies you use are clean.

WebMD Medical Reference

Next Article:

Pregnancy Week-By-Week Newsletter

Delivered right to your inbox, get pictures and facts on
what to expect each week of your pregnancy.

Today on WebMD

Woman smiling as she reads pregnancy test
Slideshow
pregnant woman with salad
Quiz
 
pregnancy am i pregnant
Article
calendar and baby buggy
Tool
 

slideshow fetal development
Slideshow
pregnancy first trimester warning signs
Article
 
What Causes Bipolar
Video
Woman trying on dress in store
Slideshow
 

pregnant woman
Article
Close up on eyes of baby breastfeeding
Video
 
healthtool pregnancy calendar
Tool
eddleman prepare your body pregnancy
Video