There are many reasons for not getting a period: 1, menstrual disorders, because of emotional changes or work and study stress, the external environment has caused endocrine disorders, so it has not been menstruating; 2, may have problems with ovarian function, ovarian function decline, premature ovarian failure resulting in amenorrhea; 3, caused by pregnancy, has not been menstruating to pregnancy test, to see if it is caused by pregnancy; 4, related to drugs, such as eaten Some people are suffering from polycystic ovary syndrome, because they do not ovulate or ovulate sparingly, so they do not get their period for several months. In which case, you can go to the hospital to check the sex hormones and also take an early pregnancy test to rule out pregnancy. Ultrasound can be done to see the thickness of the endometrium. Sometimes the absence of menstruation is also related to the adhesions of the uterine cavity.