Plan b

I had unprotected sex on September 8th then took plan b on September 10th but September 8th was the beginning of my fertile days I know its not always accurate but I was wondering whether being fertile might have increased my chances to become pregnant. I was supposed to ovulate yesterday and I don't know how plan b really works ..if someone could please explain it to me .

Please dont be rude I was never taught about this stuff thank you .