Women who have left abdominal pain and yellowish-green leukorrhea in the fourth month of pregnancy may have physiological or pathological causes, such as bacterial vaginosis. 1. Physiological reasons: After pregnancy, women may experience abdominal pain as their abdomen grows, so don’t be too nervous, you can observe it first. And if you don’t pay attention to personal hygiene and cleanliness, you may also have yellowish-green leukorrhea, pay more attention to the vulva cleaning. 2. Pathological reasons: after pregnancy, women’s body immunity is low, there may be vaginal flora imbalance, manifested as yellowish green leukorrhea, may be caused by bacterial vaginosis, this situation is recommended to improve the leukorrhea routine and other related examinations, in order to clarify the diagnosis, and symptomatic treatment. Therefore, after pregnancy, women must be regular obstetric examination, abnormalities in a timely manner to avoid miscarriage and other accidents.