Week 12

Now measuring between 2 and 3 inches from crown to rump, the fetus is busily doing his stretching and kicking exercises. All major organs are in place, and his brain, nerves, and muscles are starting to function. Although his gender was determined at conception, external genitalia won't fully develop for another couple of weeks. At that point, a sonogram may be able to show whether you're carrying a boy or a girl--if your baby will cooperate and face the camera!