When the menstruation is delayed for 10 days and the menstruation has not yet started, it is accompanied by pain in the abdomen, indicating that the menstruation is coming. Because the uterus is bleeding and the blood vessels in the pelvis are congested before the menstruation, it may cause abdominal pain or paroxysmal pain. However, if you have not had your period for more than 5 days and you have continuous pain, it is best to go to the hospital for an ultrasound to determine if there is pelvic inflammatory disease. The thickness of the endometrium should also be determined. Depending on the thickness of the endometrium, oral medication can be taken to regulate menstruation. If the endometrium is very thick, it is not recommended to take any oral medication at this time, and it is necessary to continue to wait for menstruation, even if the effect of oral medication is not particularly great.