nine weeks

Your new resident is nearly an inch long — about the size of a grape — and weighs just a fraction of an ounce, but she's poised for rapid weight gain now that her basic physical structure is in place.

She's also starting to look more and more human. Her embryonic "tail" is now completely gone and her body parts — including organs, muscles, and nerves — are kicking into gear. Her eyelids are fused shut and won't open until 27 weeks. She has earlobes, and by week's end, the inner workings of her ears will be complete. Her upper lip is fully formed, too, and her mouth, nose, and nostrils are more distinct. The tips of her fingers are slightly enlarged where her touch pads are developing.

All major joints — shoulders, elbows, wrists, knees, and ankles — are working, enabling your baby to move her limbs. As for her heart, it has divided into four chambers now, and the valves have started to develop. External sex organs are there, but won't be distinguishable as male or female for another few weeks.