Early in the pregnancy, there is a small stomach swelling and back pain, this situation may be caused by the body’s low level of progesterone. Because progesterone is the female body’s progesterone hormone, it is mainly in the female body has the role of fetal safety, if this hormone is lowered, the sensitivity of the uterus will increase, at this time some women will have a small abdominal distension, lumbago, such a symptom, so after the emergence of this situation, it is best to go to the hospital to see the body’s level of progesterone blood tests, if the low is best under the direction of the doctor, to eat some of the hormone medication to correct. If it is low, it is best to take some progesterone medication to correct it under the guidance of a doctor. In addition, some women may experience low back pain due to the expansion of the ligaments behind the uterus as a result of uterine enlargement in early pregnancy.