1-4 Weeks Pregnant

Trimester: 
First

Go to: Week 5
Return to Fetal Development Overview

Ovulation occurs - The time is right; now you just need this egg to be fertilized!

Conception occurs - Did you know that during your pregnancy that your uterus will increase its capacity by 1000 times?!

Gender is determined - Immediately upon fertilization your little one is set as a boy or a girl. Ladies, this is one that you can't take credit for since it is up to the sperm to determine the sex of your baby. Sperm carries either a "X" (girl) chromosome or a "Y" (boy) chromosome. (*Hint:* You will have to hold off on picking out the pink or blue until at least the second trimester when the gender will be visible via ultrasound.)

• Implantation - Some spotting (also known as implantation bleeding) may occur about 10 - 14 days after conception. You may believe you are starting your period but generally this bleeding is extremely light and lasts only a day or so.

Neural tube forms at 1-4 weeks of your pregnancy - It will develop into the nervous system (Brain, spinal cord, hair, and skin). Already your baby has the foundation for thought, senses, feeling, and more!

• At 1-4 weeks pregnant, heart and primitive circulatory system rapidly form - While still in its beginning stages, this is the very life support system that will carry your child throughout his or her life.

Copyright © Pregnancy.org.

Images: