Hidden pain in the stomach in the fourth week of pregnancy is considered to be related to physiological phenomena, ectopic pregnancy, pre-miscarriage and other factors. 1. Physiological phenomenon: for some women, the hidden pain in the stomach may be related to the enlargement of the uterus, thus causing tugging pain, usually no treatment is needed, and will be relieved by itself. 2. Ectopic pregnancy: for women with ectopic pregnancy, there may also be abdominal pain, or even due to the rupture of ectopic pregnancy, which may cause severe abdominal pain, fainting, shock, and endanger the woman’s life. 3. Pre-eclampsia: Women who are four weeks pregnant and have pre-eclampsia may also experience vague abdominal pain and a little vaginal bleeding. There may be other reasons for the vague pain in the stomach in the fourth week of pregnancy, so you need to cooperate with the doctor for examination if necessary, and then give treatment and therapy.