How your baby's growing: Head to bottom, your baby is approximately 5 1/2 inches long (about the length of a large sweet potato) and she weighs almost 7 ounces. She's busy flexing her arms and legs — movements that you'll likely start noticing more and more. Her blood vessels are visible through her thin skin and her ears are now in position and stand out from her head. Myelin (a protective covering) is beginning to form around her nerves, a process that will continue for a year after she's born. If you're having a girl, her uterus and Fallopian tubes are formed and in place. If your baby is a boy, his genitals are noticeable, though he may hide them from you during an ultrasound.