9 weeks, 4 days

My new resident is nearly an inch long — barely the size of a grape — and weighs just a fraction of an ounce, but is poised for rapid weight gain now that the basic physical structure is in place. Boo's also starting to look more and more human. The embryonic "tail" is now completely gone and body parts — including organs, muscles, and nerves — are kicking into gear. Eyelids are fused shut and won't open until 27 weeks. Boo has earlobes, and by week's end, the inner workings of the ears will be complete. The upper lip is fully formed, too, plus mouth, nose, and nostrils are more distinct. The tips of his fingers are slightly enlarged where the touch pads are developing. All major joints — shoulders, elbows, wrists, knees, and ankles — are working, enabling Boo to move his/her limbs. As for the 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.