Stages of Pregnancy Week by Week

What My Baby Looks Like in Week 3

In week three, a sperm and egg will unite to form a zygote, otherwise know as your future baby.

The blastocyst moves down the fallopian tube towards the uterus. If the blastocyst gets lodged in the fallopian tube before reaching the uterus, it is referred to as an ectopic pregnancy. Conception occurs upon the union of a sperm and an egg to form a single cell called a zygote. Occasionally two sperm meet two eggs forming fraternal twins (also called dyzygotic twins). The zygote soon develops into a small collection of cells called a blastocyst. A single egg is surrounded by a number of protective follicle cells that the sperm must penetrate to enter and fertilize the egg.
Illustrations Courtesy of the Sprout Pregnancy App

Illustrations Courtesy of the Sprout Pregnancy App

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An Inside Look

Take a unique look at Baby's development inside the womb this week.

Your Growing Belly

A month-by-month photo gallery of pregnancy.

Your Growing Baby

How Big is Your Baby?

Your Pregnancy Week 3

Learn more about what's happening with your pregnancy this week including your baby's latest fetal development milestones, your changing body, and tips to help you along the way.

Your Pre-Pregnancy Checklist

A healthy pregnancy begins long before that stick turns pink. Get baby-ready with these smart steps for your life, health, and finances.

Ask a Question

Got a question? We've got answers from experts and parents who've been there.

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Be prepared to share your detailed information with everyone: your medical history with your doctor, your 1 AM pickle cravings with your partner, and your contractions with your prenatal provider. Our A-Z pregnancy downloads make things easy!

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