Light, no vaginal bleeding, may be due to the gradual increase of the uterus, compression of the pelvic bones, extrusion of abdominal organs, pulling the ligaments on both sides of the uterus, stimulation of the abdominal wall nerves, leading to abdominal discomfort; 3, hormonal changes: due to the body’s estrogen and progesterone secretion during pregnancy, so that the ligamentous abdominal ligaments appear to be relaxed, inhibit the peristalsis of the gastrointestinal smooth muscle, resulting in dyspepsia, abdominal discomfort can occur. Second, pathological factors: 1, digestive tract diseases: during pregnancy due to dietary impurity, improper, can cause digestive tract diseases, discomfort around the navel may occur, usually accompanied by diarrhea, nausea, vomiting and other symptoms; 2, urinary system diseases: if the lower abdomen appears to be soreness, discomfort, accompanied by frequent urination, urinary urgency, urinary pain, may be acute cystitis; 3, gynecological diseases: pregnant women suffering from adnexitis, pelvic inflammatory disease, the abdomen will usually be Gynecological diseases: pregnant women suffering from adnexitis, pelvic inflammatory disease, abdominal discomfort usually occurs, if accompanied by abdominal pain or vaginal bleeding and other symptoms, may be the first sign of miscarriage, pregnant women need to immediately seek medical attention.