There are many reasons for stomach pain, first of all, we should see if there is any relationship between stomach pain and menstruation, stomach pain is not necessarily menstrual pain, or pain before menstruation, sometimes abdominal pain comes from other causes, such as appendicitis, gastroenteritis, this possibility; another is whether there is a pelvic inflammatory disease, it is recommended that next time the pain in the blood, or check the ultrasound of the abdominal cavity to rule out the abdominal cavity. If there is any other problem, it should be dealt with first. If there are other problems, deal with them first before considering the cause of menstruation. If you feel that the stomach pain is more closely related to menstruation, and you have stomach pain every time before your period, then go to the gynecologist for examination.