Women’s menstruation intermittently come a little bit, there are many reasons, as follows: 1, accidental pregnancy: If women have sex, did not do a good job of contraception, must exclude accidental pregnancy, especially in the case of ectopic pregnancy. The first thing you can do is to take a blood test at the hospital or use a pregnancy test to determine if you are pregnant. 2. endocrine disorders: abnormal thyroid function, hyperprolactinemia or luteinizing insufficiency. 3. other factors: such as excessive mental stress, mental tension, mood swings or poor sleep, in addition to some drugs can also affect menstruation, such as recently eaten In addition, some drugs can also affect the menstruation, such as the recent consumption of weight loss drugs, such as emergency contraceptives or short-acting contraceptives, as well as the consumption of some Chinese herbal medicines containing blood-activating ingredients. If you have recently engaged in strenuous exercise, dieting, or taking oral weight loss medication, these may cause menstrual bleeding in drips and drabs.