14 Weeks

Your adorable little fetus is busy with thumb sucking, toe wiggling, and (not so cute but equally amazing) making urine and breathing amniotic fluid as the liver, kidneys and spleen continue to develop. Lanugo (thin, downy hair) is growing all over the body for warmth. http://www.thebump.com/

Welcome to the second trimester! This week's big developments: Your baby can now squint, frown, grimace, pee, and possibly suck his thumb. Thanks to brain impulses, his facial muscles are getting a workout as his tiny features form one expression after another. His kidneys are producing urine, which he releases into the amniotic fluid around him — a process he'll keep up until birth. He can grasp, too, and if you're having an ultrasound now, you may even catch him sucking his thumb. In other news: Your baby's stretching out. From head to bottom, he measures 3 1/2 inches — about the size of a lemon — and he weighs 1 1/2 ounces. http://www.babycenter.com/