If there is a history of normal sexual intercourse, and you do not have your period on the date you are due to have your period, but you experience pain in your stomach, you must clinically exclude the possibility of ectopic pregnancy. You can go to the hospital to have blood drawn for blood HCG to find out if you are pregnant. If pregnancy is indicated, it is recommended to take blood tests every other day to find out whether the blood HCG has doubled, if it has not doubled, ectopic pregnancy is highly suspected clinically, and hospitalization is needed to give appropriate treatment. If there is no pregnancy, menopause and stomach pain, it is recommended to do ultrasound examination to find out whether there is any abnormality in the uterine adnexa. If the uterine adnexa is normal, you can take progesterone orally to promote menstruation, once a day, 2 capsules at a time, for 3 days, after stopping the drug 3-7 days after the menstruation, and also recommended to drink brown sugar and ginger water, which has the effect of driving away the cold and warming up the uterus, and can ease the pain in the stomach.