Abortion a few days abdomen still aches what reason be

Usually after female abortion, uterine contractions will continue to occur, and some tissues will remain inside the uterus, which need to be excreted, which will also cause uterine contractions, so it will cause pain, which usually lasts for about three days, which is a normal phenomenon, but if it lasts too long, even more than a week, it is necessary to be alert to infection inside the uterus.