Tummy discomfort in early pregnancy can be caused by the following reasons: The first reason is that as the uterus increases in size, there is a corresponding pulling pain in the uterine ligaments. However, this pain is often mild, so the stomach may become uncomfortable. It is recommended to take proper rest and avoid heavy physical work during pregnancy. The second reason is caused by pre-eclampsia, such as progesterone deficiency, which often causes contraction of the smooth muscle of the uterus, so the stomach will feel uncomfortable. It is recommended to check the blood HCG and progesterone to know if this condition exists. The third reason is that after pregnancy, estrogen increases a lot and the mucous membrane of the gastrointestinal tract may become slightly edematous, so clinically there will be discomfort in the gastrointestinal tract, which will be manifested as discomfort in the stomach.