My Period Just Ended Oct. 25th I Had Unprotected Sex

My Period just ended Oct. 25th I Had Unprotected Sex Yesterday Night. (Iknow That was my Fault ) But He Said he Didn't Finish inside me But I'm pretty SURE he Got out a bit late not everything but a Little late . So I went on to my local pharmacy and Bought a Plan B Pill 30 Min. After But I'm Really Scared to end up pregnant since everyone is telling me I will end up .