First Trimester Changes -- What's Happening to You and Baby?

Week 10: Your baby's nearly two inches long. If you could look inside, you'd even see ankles and wrists. Several more organs begin functioning this week including the thyroid gland and gall bladder.

Week 11: Your baby has already developed sleeping and waking cycles, usually between 5 and 10 minutes long. The body and limbs are catching up with the head. Your little babe looks more like a tiny person. The organs finalize shapes and functions, glands pump out hormones and intestines form. The skin thickens and tiny hair follicles appear. Vocal cords begin forming, too.

Week 12: All major organ systems have finished developing. Now they just need to grow. Your baby will be about three inches long. The nose, eyelids and ears are in place. Some researchers say they can detect variations in personality even this early, like whether your baby will be calm or active, a thumb sucker or not.

What kinds of experiences are you going through? Did you know all these things were happening?