This is when the cervix opens and the placenta breaks free from the uterine wall. This can be identified with pains like bad period pain or birth contractions. Heavy bleeding or passing pieces of placenta which look like blood clots or liver also indicate the miscarriage. The patient can feel faintness and nausea. If the miscarriage is due to an incompetent cervix, after 16 weeks everything will happen very quickly and the baby may be born alive.