The stomach of five and a half months pregnant a little bit of pain and then tightening and swelling may have a certain relationship with physiological contractions, pre-miscarriage. 1. Physiological contractions: 5 months of pregnancy, the fetus is almost fully developed, can be free in the uterus, if the activity range is large, can stimulate the appearance of physiological contractions, caused by the stomach tight and hard. Generally, you can pay more attention to rest, do not overwork. 2. Pre-eclampsia: When a pregnant woman is five and a half months pregnant, the abdominal skin is tight and hard, and if it is combined with lower abdominal pain, vaginal bleeding, vaginal fluid and other abnormalities, usually suggests that it is pre-eclampsia. If a pregnant woman is experiencing uncomfortable symptoms, it is recommended that she consult a doctor in a timely manner, complete the relevant examinations, identify the cause under the guidance of a specialist, and actively deal with it.