Congratulations! This week marks the half way point of your pregnancy. It has been 18 weeks since the date of conception and your baby's crown-to-rump length is 5.6 to 6.4 inches. The fetus weighs about 9 ounces and your belly definitely has an obvious bulge. Your baby's skin begins to thicken this week and will develop four layers. Scalp hair and toenails are beginning to form at this point. Hair can also be seen on the upper lip and eyebrows.