Brown discharge always appears on the underwear at the beginning of pregnancy, considering cervical disease, preeclampsia, ectopic pregnancy and other reasons. 1. Cervical diseases: cervicitis, cervical fibroids, cervical polyps and other diseases can lead to the appearance of brown discharge. The main reason is that these diseases can lead to tissue proliferation, causing inflammation of the cervix, which can lead to vaginal bleeding. 2. Pre-eclampsia: During a miscarriage, the embryonic chorionic villi detach from the uterine cavity causing uterine contractions, which can lead to vaginal bleeding. 3. Ectopic pregnancy: Ectopic pregnancy can cause abnormal thickening of the uterine lining, resulting in exfoliation of the uterine metaphysis, thus causing vaginal bleeding. Therefore, if there is brown discharge in the early stage of pregnancy, you should go to the hospital in time for examination and consultation, early diagnosis and early treatment.