The main drugs used to delay menstruation are progestational drugs, such as progesterone or progesterone. If patients take these drugs regularly to delay menstruation, it will cause disruption of progesterone secretion in the body, thus causing adverse reactions to the drugs. There will be constant vaginal bleeding, irregular vaginal bleeding, or even risk of hemorrhage in severe cases, and some patients may have prolonged or shortened menstrual cycles. The normal menstrual cycle is due to the influence of hormones secreted by the human body on the uterine ovaries and the clinical manifestations of the disease.