Brown blood flow in the 5th month of pregnancy is considered to be a possible preterm miscarriage. During this period, it will be accompanied by stomach pain, or a tight and hard stomach, you should pay attention to bed rest and observe the size of the bleeding. In the 5th month of pregnancy, if there is a pre-eclampsia miscarriage, it needs to be treated with symptomatic medication under strict medical supervision. If there is only brown blood flow and no stomach pain, you should observe if there is any odor. If there is vaginitis or cervicitis, there will also be brown blood, but the blood flow will not be too large, and there will be leucorrhea accompanied by odor. If the symptoms persist, you need to seek medical attention.