Do I even take Plan B now?

So my bf and I had unprotected sex last week (the day I was 1 day late) and when I was cleaning myself with a towel, I noticed a bit of pink blood but no period yet. Then 2 days later, (no period yet) we did it again unprotected and he came in me because I was going to take a Plan B right after but today, being the day after, I was cramping bad in the morning while being 5 days late and once I went to the bathroom, I noticed my period started. Sooo, my question is, do I still take the pill even though I was late for 5 days and now today I got my period?? My fertile window was a little more than 2 weeks ago, so I don't think I was able to get pregnant. Any thoughts?

Update: I'm aware that plan b isn't birth control and I don't abuse it or used it, but I just wanna know if it'll even work even though I was late then the next day after sex I got my period.