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Guide to Being 13 Weeks Pregnant

What's Going On in Your Body

Size: About 3 inches. Weight: About an ounce. Bones: Starting to form.

That little guy or gal in your uterus is looking even more human this week, with a body size that's slowly catching up to that giant head, the beginning of bones in arms and legs, eyes that are moving even closer together, and an easily determined sex (although you probably won't detect it on an ultrasound for several more weeks).

Around this week, too, your breasts might be in the early stages of colostrum production. That's the fluid that will nourish your newborn in the first days after birth if you're breastfeeding.

Also during week 13:

  • Intestines are shifting from the umbilical chord into the abdomen.
  • Vocal chords are starting to develop.
  • Fingerprints are forming on those tiny, no-longer-webbed fingers.
  • The fetus can move his or her limbs.
  • A girl now has a couple million eggs in her ovaries.

With all the activity going on inside you, your partner might be feeling a bit outside of things. But make no mistake, your significant other is a crucial part of the equation right now …