Many changes occur in a woman's body during the 15th week of pregnancy. FitPregnancy.com states that in addition to a noticeable bump below the belly button, the body also practices production of colostrum, a protein-rich fluid that provides nutrition for newborns. This may cause the nipples to leak. As the uterus prepares for birth, the expectant mother may start to feel light contractions, known as Braxton-Hicks contractions.
In addition to changes in body shape, What to Expect states that changes may occur in the expectant mother's mouth. Pregnancy hormones can cause gums to become sensitive and prone to swelling and bleeding when a woman brushes or flosses. These same hormones cause gums to react differently to the bacteria in plaque, making the woman more susceptible to gingivitis. Gingivitis can spread to infect the bones of the jaw and other tissues surrounding the teeth, so good dental hygiene is recommended. Brushing twice a day and flossing gently once a day can reduce gum bleeding and swelling.
FitPregnancy.com states that by the 15th week, the baby reaches an average length of about 5 inches and weighs about 2 ounces. The nose, lips and taste buds are formed, and the baby's head is covered in fine hair called lanugo. What to Expect says that during active periods, the baby begins to practice breathing, sucking and swallowing motions to prepare for life outside the womb. The baby is also kicking, curling its toes and moving its hands and arms, although most of these motions go undetected by the mother at this stage.