My boyfriend and I are freaking out over plan b?

So things happened before I took plan b. Like a week before we had a quicky. Than a week after that we.. ya know.. and after that I took plan b right after that, but then the next day we did it again, but that one was more of a quicky too. We weren't safe, but he checked for pre ***. It wasn't there but still you never know what could happen. So idk :( im supposed to start on sunday but plan b can set your period back and now idk when it should come. I feel fine though, nothing out of the ordinary. HELP