8 weeks

How your baby's growing: Your baby is now 5/8 of an inch long, about the size of a kidney bean. She's constantly moving and shifting, although you won't be able to feel these womb wiggles for several weeks yet. Her embryonic tail is disappearing, and her eyelids practically cover her eyes. Still slightly webbed, her fingers and toes are growing longer. Her arms have lengthened, too, and her hands are now flexed at the wrist and meet over her heart. Her knee joints have formed, and her feet may be long enough to meet in front of her body. With her trunk straightening out, her head is more erect. Breathing tubes extend from her throat to the branches of her developing lungs. The nerve cells in her brain are also branching out to connect with one another, forming primitive neural pathways. Though you may be daydreaming about your baby as one gender or another, the external genitals still haven't developed enough to reveal whether you're having a boy or a girl.