Taking the pill too little menstruation may be the side effects of the pill or contraceptive failure after a pre-eclampsia miscarriage or combined diseases, there is bleeding phenomenon, will be mistaken for menstrual blood, it is recommended that patients after a clear diagnosis, according to the different causes of treatment. Common causes and treatments a. Side effects of the pill 1, withdrawal bleeding: the sudden rise and fall of hormone levels after the pill, resulting in endocrine disruption, mistaken for menstruation, usually occurs in the 5-7 days after taking the pill, for spot bleeding, the amount of small and short duration than normal menstruation, no special treatment; 2, endometrial thinning: the pill contains progestin, inhibit the growth of the endometrium, endometrial thinning leads to Menstrual blood volume decreased, can first follow the observation for 2 months, and after the drug metabolism will generally resume normal menstruation. The pregnancy can be confirmed by checking the human chorionic gonadotropin in the blood, usually the bleeding is relatively small, irregular bleeding, which can be bright red or light red, usually without blood clots, accompanied by lower abdominal cramps. Oral progesterone can preserve the fetus, and when miscarriage is unavoidable, perform a curettage; 2. Ectopic pregnancy: the fertilized egg is implanted outside the uterus, the bleeding is irregular and small, dripping, and the embryo rupture can lead to hemorrhage or even shock, the ultrasound can confirm the diagnosis of ectopic pregnancy, and the pregnancy should be terminated in time. Chronic endometritis: bacterial infection is the main cause, but it can also be secondary to other diseases such as uterine fibroids and vaginitis, which can lead to reduced menstrual flow, abdominal cramps and pains, and abnormal leucorrhea. If the patient has too much or too little thyroid secretion, it can also lead to amenorrhea, thinning hair, etc. It is necessary to promptly check the level of thyroxine and perform targeted treatment such as thyroxine supplementation or compound iodine treatment. The use of birth control pills can affect menstruation and can be harmful to a woman’s body, especially emergency contraceptives. If there is no pregnancy plan, it is recommended to use condoms and IUDs to prevent pregnancy, which is more effective.