###Human: My period is heavy after taking ECP in this cycle. Why? ###Assistant: Hi, Welcome to iclinig.com. Considering your periods to be regular in general, you had intercourse in a safe period. Secondly, you also took an emergency contraceptive pill and took a blood test to rule out pregnancy. There are nil chances of pregnancy. Your heavy periods are due to the EC (which contain high dose of progesterone) side effect. It should wane off gradually. You also have a chance of the next period to be a bit irregular and heavy.