Hallow Dear, Usually the clot of abortion is whitish in colour and sticks to the center of the sanitary napkin. Though there is a good chance that this could be menstrual cycle, such a severe pain is suggesting a possibility of miscarriage or ectopic pregnnacy. Ultrasonography may guide you in diagnosing the condition. More likely possibility is Ectopic pregnancy. In this condition, initially there is very little bleeding and then it may increase; however severe abdominal pain is a classic feature of ectopic pregnancy. In this condition, there is profuse intra-abdominal bleeding and you require blood transfusions and surgical intervention. Please report to your Obstetrician ASAP. Ultrasonography at early stage may not be conclusive. I hope you got the message. Dr. Nishikant Shrotri