Pregnancy pain in the lower abdomen may be caused by the following reasons: a. The gradual increase in the size of the fetus will lead to an increase in the size of the uterus, so there will be abdominal pain, which is a normal phenomenon. Second, the lower abdominal pain in early pregnancy may also be caused by ectopic pregnancy, so go to the hospital in time to do abdominal ultrasound to determine the intrauterine pregnancy. Third, taking cold food can also easily cause abdominal pain, accompanied by diarrhea symptoms, you can drink more warm water to relieve abdominal pain, you can also use hot water bags for hot compresses on the abdomen. In addition to the above reasons, lower abdominal pain in the second trimester may be caused by pseudo contractions, so be sure to pay attention to more rest, do not overwork, also go to the hospital on time for pregnancy checkups, if there is redness or broken water and other symptoms to go to the hospital in a timely manner.