Tummy pain in the 4th week of pregnancy can be seen as physical pain caused by pregnancy and also other abnormal conditions. 1, physiological phenomenon: If it is clear that the early pregnancy in the uterus, at this time the hidden pain in the stomach is mainly considered to be physical abdominal pain caused by pregnancy, which is a normal physiological phenomenon, because the early embryo bed destroys the endometrium, the hormone level changes in the body leading to accelerated metabolism in the body may induce abdominal pain. Often manifested as a short period of time, the lower abdomen on both sides of the attack, exacerbated by exertion, can be relieved after lying down to rest. 2. Pre-eclampsia or miscarriage: If early intrauterine pregnancy is clear and the stomach pain does not ease or worsen after resting for 4 weeks of pregnancy, or even accompanied by a little vaginal bleeding, the possibility of pre-eclampsia is not ruled out, and the blood HCG and early pregnancy ultrasound need to be rechecked at the hospital immediately for clarification. 3.Ectopic pregnancy: If there is no clear intrauterine pregnancy, stomach pain at 4 weeks of pregnancy needs to be alerted to the possibility of ectopic pregnancy, which requires immediate medical attention, because the condition of ectopic pregnancy progresses rapidly and can cause syncope and shock when rupture occurs, which can endanger life. 4, other diseases: If you have not been to the hospital, but the urine test paper test at home is positive, you can not exclude the possibility of false pregnancy, and the vague stomach pain does not exclude gastroenteritis, pelvic inflammatory disease, appendicitis and other causes. In summary, stomach pain in the fourth week of pregnancy can be due to normal physiological phenomena, but also to pre-miscarriage, ectopic pregnancy or other diseases. If you experience stomach pain in early pregnancy, for safety reasons, you should go to the hospital in a timely manner to clarify the cause, and not to carry it at home to avoid ectopic pregnancy rupture and hemorrhage, which may endanger your life.