hi, i had protected sex (wearing condom)with my girlfriend on 2nd oct, to be on a safer side i asked her to consume unwanted-72 pill , 2-3 days later she told me about her bleeding for 3-4 days, like an irregular periods, now my concern is her cycle starts on 18th of every month but this month she hasn t got her period yet, please let me know what could be the reason, please help. Thanks,