If your period is delayed for 15 days, you should choose the treatment according to the cause of the delayed period. The common causes and treatments are as follows: 1. Pregnancy: For patients who are young and have a regular sex life, if your period is delayed for 15 days, it is recommended to buy a pregnancy test from a pharmacy first or go to the hospital to check whether you are pregnant. If pregnant, you can go through the normal pregnancy test process. 2. Physiological factors: If you are not pregnant, you need to consider whether it is due to medication, weight loss, overexertion, anxiety, etc. Usually, if you stop the medication, resume normal diet, take good rest and avoid anxiety, your period will come within a short period of time; 3, irregular menstruation: if the patient has avoided the causes of delayed menstruation, but your period still cannot come normally, you can go to the hospital and take progesterone drugs to eat, usually your period will come normally about 7 days after you stop the medication; 4, primary diseases: if it is due to polycystic ovaries, hyperprolactinemia, hypothyroidism If the delayed menstruation is caused by polycystic ovaries, hyperprolactinemia, hypothyroidism, the use of appropriate drugs for the treatment of the primary disease, can also make the normal menstruation; 5, perimenopausal syndrome: some patients aged 40-50 years old because of perimenopause caused by delayed menstruation, it is recommended to check the sex hormones in the hospital first, to determine whether it is because of the perimenopause. If it is indeed due to the decrease of estrogen level during perimenopause, which leads to delayed menstruation and becomes menstrual flow for 45 days/time, it is basically a relatively normal situation, and patients usually pay attention to calcium supplementation, and when perimenopause is over, patients may experience amenorrhea.