hello doc.last time i was down with periods on 8th sept.(that was 20 days aftr the previous one).and i had  sex wiith my bf on 17th sex which was unprotected..so out of scare i took 2pills ie one in just  aftr 2hrs and another aftr 24hrs...today its 24th sept and still i havnt got my periods...i had taken a pregnancy test by the kit also..that showed negative result..so what should i do now..am i pregnant or not.?