The feeling of menstrual cramps at the beginning of pregnancy may be physiological, or it may be the precursor of miscarriage or ectopic pregnancy. 1. Physiological: After pregnancy, the uterus gradually increases in size, and the discomfort caused by the uterus stretching the nerves in the pelvic cavity may appear like menstrual cramps. 2. Miscarriage precursor: due to the unhealthy development of the embryo, the precursor of miscarriage occurs, causing abdominal pain, may be accompanied by a small amount of vaginal bleeding, you need to go to the hospital in a timely manner for blood human chorionic gonadotropin HCG and progesterone, ultrasound, etc., in order to understand the embryo’s development of whether there is any abnormality. 3. Ectopic pregnancy: due to the pregnancy sac did not enter the uterine cavity in a timely manner, in the fallopian tube or other location of the bed growth, can cause abdominal pain, ultrasound if the uterine cavity does not see the pregnancy sac, in the fallopian tube or other location of the diagnosis of pregnancy, the need for timely conservative treatment or surgical treatment, and so on. If you are pregnant and have menstrual cramps, you need to go to the hospital in time to get a clear diagnosis, and deal with it scientifically under the guidance of your doctor.