Aunt i.e. menstruation, the feeling of menstruation in the abdomen at the beginning of pregnancy may be caused by changes in hormone levels in the body, pelvic inflammatory disease, preeclampsia and other manifestations. 1. Changes in hormone levels in the body: in early pregnancy, pregnant women’s body progesterone human chorionic gonadotropin, progesterone and other sex hormone levels increase significantly, may cause pelvic tissue congestion, may cause early pregnancy abdomen with menstrual feeling. 2. Pelvic inflammatory disease: If bacteria and other pathogens enter the pelvic cavity during the early stage of pregnancy, they may cause localized inflammatory edema and exudation, which may lead to the feeling of menstruation in the abdomen, which may be accompanied by fever, increased secretions and other symptoms. 3. Pre-eclampsia: In the early stages of pregnancy, if the pregnant woman is affected by various pathogenic factors, the gestational sac is separated from the uterine wall in a small amount, which may cause the above performance. The causes of the feeling of menstruation in the abdomen at the beginning of pregnancy are many and need to be diagnosed and treated under the guidance of a professional doctor.