Missed period/Plan B/Pregnant?

So it started like this... I took a plan B a couple of months ago after a little mishap. That plan b has changed my cycles tremendously. I had one period since I took that thing. My cycles went from 28 days to 50+ days 😩

Okay so currently I am awaiting my period that was supposed to be here November 16th (20 days late) My period before that one was October 24th. This really didn’t alarm me because like I said that plan b messed me up.

Sunday night my bf and I had sex & he didn’t withdrawal. How many days should I wait to take a test? Should I be looking for symptoms anytime soon?