Dear Rashi puttar, emergency contraceptive pills do affect the menstrual cycle so it's not surprising for periods to be irregular after the pill. These pills are for EMERGENCIES only and very trustworthy, so pregnancy chances are not the same after taking it, but if you have any doubts, take a home pregnancy test and make sure of the situation. Please use a condom next time. Read here: https://lovematters.in/hi/resource/safe-sex https://lovematters.in/hi/birth-control/top-10-facts-about-emergency-contraceptive-pills If you would like to join in on a further discussion on this topic, join our discussion board, ‘Just Ask’ https://lovematters.in/en/forum