Menstruation was delayed for two days, accompanied by vague pain in the abdomen, can be seen in the following cases: First, early pregnancy patients usually regular menstruation, the recent period of sexual intercourse without contraception, menstruation delayed for two days, there may be early pregnancy. You can do your own pregnancy test or go to the hospital for a blood test HCG, in order to make a clear diagnosis; Second, gynecological endocrine disorders, gynecological disorders caused by endocrine disorders, can cause hormone secretion disorders. The most common blood polycystic ovary syndrome, often clinically manifested as menstrual disorders, infertility, weight gain, hair growth and so on. After a clear diagnosis, medication should be administered under the guidance of a doctor; Third, simple delayed menstruation, because of the effects of weather changes, adverse mood changes, environmental changes and other influences, thus leading to the delay of menstruation, usually affecting only one menstrual cycle, and will not have an impact on the next menstrual cycle. They are usually given temporary observation and do not need to be treated.