Usually patients with early pregnancy do not cause symptoms of stomach pain. If patients with early pregnancy have abdominal pain, the possibility of acute abdomen will be considered first. Clinically, it is common such as acute appendicitis, acute enteritis, or some other abdominal diseases. Ultrasound examination is needed to exclude other diseases and then diagnose the situation for early pregnancy. Early pregnancy is caused by the enlargement of the uterus or the enlargement of the uterine ligaments around the uterus, causing distension and discomfort in the abdomen, which is different from the pain in the abdomen caused by acute abdomen. The pain caused by acute abdomen is more intense and unbearable, while the pain of early pregnancy is mild and can be tolerated by the patient.