Hi. I had my last period april 2,2016-april 6,2016 then two days after my menstruation we had unprotected sex on april 8 and april 9. I took postinor 1 the next day. A week after i had very light dark brown bleeding for 5 days. Now its May 7,2016 and i still dont have my menstruation. I should have it May 2,2016. I tried home pregnancy test 4 times. May 2,2016 May 4,2016 May 6,2016 and May 7,2016 and it all came negative. I have stomach cramps sometimes and nothing else. Im still worried why i still dont have my menstruation.