Dear Mary, periods are sometimes becomes irregular because of stress, tension and hormonal changes also. But if you had an unsafe sex before, first of all to assure yourself - do a home pregnancy test - morning urine sample is the best. And then please consult a specialist or a registered doctor soon. Read here also: https://lovematters.in/hi/resource/menstrual-cycle https://lovematters.in/hi/our-bodies/my-periods-are-irregular-what-should-i-do https://lovematters.in/hi/pregnancy/home-pregnancy-tests-dos-and-donts If you would like to join in on a further discussion on this topic, join our Facebook and Instagram: https://instagram.com/lovemattersindia?igshid=YmMyMTA2M2Y= https://www.facebook.com/lovematters.india?mibextid=LQQJ4d