Hello Thank you for your query. Firstly it is possible that the I pill has interfered with your natural cycle. I pill can prepone or delay your periods by a week or so. However, I pill is never a substitute for a regular contraceptive method. it is very simple that if you have missed your period, please take a home urine pregnancy test tomorrow morning, so that you would know for sure that you are pregnant or not. If the test is positive, please consult a gynecologist at the earliest for advice on termination. Have protected sex in the future. Take care.