How long is it normal for menstruation to be delayed?

　　Generally, the menstrual cycle is about 25 to 35 days. Before having sex, pregnancy should be ruled out first. Hospital Check blood HCG to confirm whether you are pregnant. If not, there are many factors that affect menstruation. Common ones include abnormal ovarian function. Uterus disease , uterine diseases, endocrine dysfunction, etc., you can come to the hospital for six hormone tests using electrochemiluminescence immunoassay to understand the endocrine situation. Combined with vaginal four-dimensional color ultrasound to determine whether there are any abnormalities in the uterus and ovaries, diagnose the cause and then treat it symptomatically. Do not treat blindly. In addition, environmental factors and mental factors also have an impact on menstruation. Occasionally, an abnormality can be observed.