The pain in the belly during ovulation is often caused by the following reasons: 1. After ovulation, the corpus luteum forms and there is a small amount of bleeding inside the corpus luteum, which increases the local pressure inside the corpus luteum, so there is pain in the belly, but this pain is often a vague pain, which is usually tolerated. The pain is often vague and can be tolerated. and after a day of rest, the abdominal pain will be significantly relieved the next day. 2. because of chronic pelvic inflammatory disease, the lower abdominal pain caused by the stimulation of follicular fluid flowing into the rectal fossa of the uterus during ovulation, can be treated as long as the pelvic inflammatory disease is actively treated. The symptoms of lower abdominal pain will disappear at the time of ovulation, which is the lower abdominal pain caused by the rupture of the corpus luteum, which is relatively severe and may cause nausea and vomiting. It is advisable to go to the hospital in time for examination to make a preliminary diagnosis, which can be treated conservatively or surgically.