When you experience pain during menstruation at 40 weeks of pregnancy, it is possible that you are going into labor, but it can also be due to other reasons. When menstrual pain occurs at 40 weeks of pregnancy, if it is accompanied by the phenomenon of redness and regular contractions, the possibility of labor is more likely, and it is recommended to go to the hospital in time for labor. However, at 40 weeks of pregnancy, the simple appearance of stomach tightness, hardness, and the range of symptoms of mild pain, mostly indicates that it is the manifestation of premonitory labor, not necessarily to labor. The pain that occurs when you have your period at 40 weeks pregnant can also be caused by the ligaments around the uterus being stretched due to the increasing size of the fetus. Therefore, 40 weeks pregnant out of the stomach like the pain of menstruation, it is recommended to go to the hospital in time, after the doctor’s interview combined with other related items of examination, to clarify whether it is necessary to birth.