Question!!!

So last Friday August 23 I had sex and I performed oral sex before we started messing around and he came then we started messing around then he put a condom on. I wasn’t on birth control at the time because I was waiting for it to come in the mail so I took take action (generic plan b) an hour later because I kept panicking afterwards. And then on Monday August 26 I started my new birth control and I’m supposed to get my period on Tuesday. Soooo my question is will I get my period or not? Did I mess myself up? Do I need to test just in case?