15 weeks

Your growing baby now measures about 4 inches long, crown to rump, and weighs in at about 2 1/2 ounces (about the size of an apple.) She's busy moving amniotic fluid through her nose and upper respiratory tract, which helps the primitive air sacs in her lungs begin to develop. Her legs are growing longer than her arms now, and she can move all of her joints and limbs. Although her eyelids and stil fused shut, she can sense light. If you shine a flashlight at your tummy, for instance, she's likely to move away from the beam.