After having sex during pregnancy, there is a bulging of the abdomen. This phenomenon should be highly alert to the possibility of uterine contraction due to sexual stimulation, once the uterus contracted under the stimulation of sex, it is easy to cause miscarriage. Pregnant women should pay attention to this situation, try to rest in bed, do not carry out physical labor and physical activities, especially absolutely prohibit sexual intercourse. In most cases, the symptoms can be relieved quickly with proper rest and will not cause serious problems. If the symptoms of abdominal distension are not relieved after rest, but further aggravated, or obvious pain symptoms, vaginal bleeding phenomenon, you should go to the hospital as soon as possible for treatment of birth control.