The reaction of a fertilized egg at the time of implantation varies from person to person. Most people have no symptoms at the time of implantation, and only a few will experience back pain or abdominal distension. Although most people do not feel anything when the fertilized egg is implanted, the fertilized egg is after all a new organism and therefore may cause slight bleeding in the endometrium during implantation, and some people may experience mild abdominal pain and back pain, and may also experience a slight drop in body temperature, which usually resolves in 2-3 days. If the symptoms of lumbar pain or abdominal distension persist without relief, pelvic ultrasound and examination of the lumbar spine are recommended to rule out other gynecological inflammatory diseases or lumbar strain. After successful fertilization of the egg, there is a possibility of embryonic abortion in early pregnancy, so women should pay attention to rest, avoid frequent labor and strenuous exercise, regular pregnancy tests, and seek medical attention if there is discomfort or aggravation of abdominal pain to prevent accidents.