Menstruation did not come, the flow of brown dirt, consider pregnancy, may also be normal to menstruation. The reasons are as follows: 1, if the normal regular menstruation over the period, and have sex, did not take safe and effective contraceptive measures, the brown discharge is considered to be pregnant, the body of estrogen, progesterone levels in the early stages of pregnancy, or the embryo’s own developmental anomalies, the occurrence of aura miscarriage. It is recommended to go to the hospital in time to check, according to the specific circumstances of the treatment of birth control. 2, the estrogen level before menstruation is not stable fluctuations, there will be brown secretions, a small amount of endometrium due to the loss of estrogen to support the shedding of the bleeding caused by a small amount of bleeding, not discharged in a timely manner, the blood in the blood haemoglobin is oxidized, brown or rust color, do not have to deal with.