Delayed periods. Per day for 5 days.

I had unprotected sex of 5 th day of periods... but within 3-4 hours i took unwanted 72... My period cycle is of regular 28 days... But my periods got delayed by one month... That means i had periods in june... But i skip the periods of july month .. i also took pregnancy test but it was negative... N i took pregnancy test after missing my period date... Then after one month of missing my period.. doctor prescribed me primoult-n two tablets per day for 5 days... After completing the course i got my periods.after 4 days of course completion..... Or i thought so... There was normal bleeding like my periods.. or i can say it was little less... But there was not much difference... In short it seems like that it was my normal period... So i wanted to ask that is there any possibility of PREGNANCY now... I just want to be sure that i m not pregnant...