Whether or not low menstrual flow affects pregnancy depends not only on menstruation but also on ovulation. Low but regular periods with normal ovulation usually do not affect pregnancy. If there is no normal ovulation, pregnancy will be affected. There are many factors that affect menstruation. Environment, diet, emotions, work and rest, stress, etc. may affect the endocrine balance and lead to changes in menstrual flow. If the menstrual flow is low but has been regular and has not affected ovulation, pregnancy is usually not affected. If the amount of menstruation suddenly decreases and hormone levels are found to be disturbed, it is likely that ovulation will be affected, and pregnancy will be affected at this time. It is recommended to go to the hospital in time and do relevant examinations, such as hormone six tests and abdominal ultrasound, to take treatment or therapy after a clear diagnosis.