The left side of the stomach pain in the second month of pregnancy may be caused by the following factors: 1, caused by the enlargement of the uterus, because at this time the fetus is gradually developing, if the uterus stimulates the lower edge of the rib cage, pregnant women will have symptoms of stomach pain. As the enlarged uterus triggers stomach pain is a normal physiological phenomenon and does not require special treatment.2. Pregnant women who consume frozen or spicy food in early pregnancy may also suffer from acute gastritis, gastroenteritis and other diseases, resulting in abdominal pain and diarrhea.3. Pregnant women with left-sided stomach pain in early pregnancy may be caused by pre-eclampsia or ectopic pregnancy, mostly accompanied by vaginal bleeding, continuous lower abdominal cramps The patient needs to go to the hospital for treatment in time.4. Pregnant women who have placental abruption may also have symptoms of stomach pain.