I took plan B about 1hr - 1.5hrs after having unprotected sex, should I be well protected.?

My boyfriend of 6 years (we are currently 20 & 21) had unprotected sex yesterday. We usually use protection, but we had run out of condoms and decided it would be okay to go one time without it. Well, he ended up finishing inside me. Directly afterwards we went to purchase plan B, which I took about an hour to an hour and a half after we had sex.

I am unsure of when I ovulated last because my periods are not 100% regular; However, my last period ended at the very beginning of May, so it could've been anytime between last week and this week (I also have signs when I am around that time such as breaking out, weird discharge, etc.) I will also add that I am not on any kind of birth control.

So my ultimate question is: I took plan B about an hour - an hour and a half after having unprotected sex, should I be well protected against pregnancy? I am just extremely worried and I also fully understand that this was a stupid decision on my part.

Thanks in advance!