There is no abdominal pain but vaginal bleeding in the third month of pregnancy, two possibilities are mainly considered: firstly, the abnormal position of the gestational sac in the bed, so the placenta grows in an abnormal position, for example, the placenta is in a lower position, reaching the inner cervical opening or covering the inner cervical opening; or because of the cesarean delivery, the placenta is positioned on the scar of the cesarean delivery and the implantation of the placenta occurs, both of which can lead to painless abdominal pain. If it is these two cases, we must pay attention to it, must rest in bed, continue to observe, and in special cases need to do abortion. Secondly, it is seen that the pregnant woman herself may have cervical polyps, cervical lesions, vaginal inflammatory diseases, etc., which may not be related to pregnancy, but, after pregnancy, due to local congestion of the uterus, cervix and vagina, so, there may be bleeding, which needs to be dealt with according to the specific examination results.