The endometrium is affected by the cyclical changes of ovarian hormones and the periodic bleeding is called menstruation. The cyclic changes in the endometrium are called the menstrual cycle, which is also the human reproductive cycle. The normal menstrual cycle is 28 days, and a week earlier or later can be considered a normal menstrual cycle. The menstrual cycle can be divided into three phases: follicular phase: corresponding to days 5-14 of the menstrual cycle; luteal phase: days 15-28 of the menstrual cycle, during which the endometrium is preparing conditions for the arrival of a fertilized egg and its implantation; menstrual phase: if pregnancy is not successful in this cycle, the endometrium peels off and bleeds under the influence of ovarian hormones and lasts about 3-7 days. Pregnancy begins with the union of sperm and egg, which travels back to the uterine cavity after the union of the fallopian tubes, where it is planted in the endometrium through a complex process in the following 7-8 days and begins to grow and develop further, while the endometrium under the influence of hormonal levels in the body undergoes meconium-like changes to further maintain the pregnancy state so that it does not peel off and menstruation occurs. Therefore, menopause is one of the key symptoms for clinicians to diagnose early pregnancy and is the earliest symptom. So how many days without menstruation indicates pregnancy? For women with regular menstruation, pregnancy should be considered when there is no menstruation beyond the usual menstrual cycle, while for women with irregular menstruation, it is “unreliable” to rely on the symptom of menopause to diagnose pregnancy, and therefore many women with irregular menstruation fail to detect pregnancy in time for early pregnancy. However, it is worth noting that the clinical diagnosis of pregnancy should not be based on menopause alone, but should be combined with related clinical symptoms, such as early pregnancy reaction, breast tenderness, weakness, drowsiness, etc. A more accurate diagnosis should be made with the help of related auxiliary tests, such as urine early pregnancy, blood HCG, pelvic ultrasound, etc. In addition, after menopause, you should be alert to the occurrence of abnormal pregnancy, such as ectopic pregnancy, gravida, etc. Therefore, you should go to the hospital as soon as possible to confirm the diagnosis of pregnancy and whether it is a normal pregnancy.