I Was Sensing Pregnancy But D Two Tests I Did

I was sensing pregnancy but d two tests I did was negative, so I concluded it was my ulcer that is nauseating me. Along d line I had unprotected sex and after 9hrs I took postinor 2, after 5days, I was bleeding which lasted 3days, should I still nurse the fear of being pregnant or since I bled after taking postinor 2 it means I am not pregnant?