The low placenta and how long it takes for the brown blood to clear depends on the specific situation of the pregnant woman and cannot be generalized. Because the placenta is low and the edge of the placenta is close to the cervical os, the placenta tends to detach at the edge of the inner cervical os, resulting in vaginal bleeding. Patients may experience significant vaginal bleeding of bright red or brown blood after exertion or strenuous exercise. If a pregnant woman does not have continuous contractions and the cervix is open, the placental abruption bleeding is small and usually stops after 1-2 days of small amounts of brown blood. In some patients, a small amount of brown blood in the first stage may be followed by heavy bleeding in the later stage, which cannot stop on its own and should be treated immediately in hospital. Therefore, if you find a low lying placenta with vaginal bleeding, you should not wait for it to stop on its own, but should immediately consult with the obstetrics and gynecology department to avoid delaying the condition.