Should I worry?

Okay so I had sex the first day the app said I was ovulating. He pulled out but I still got plan b. Since then my period has been all messed up. I was spotting for about 14 days and then what I thought was my actual period, finally came. It wasn't that heavy but wasn't spotting either and it only lasted like 3 days. I had sex the other day (I was near the end of what I thought was my period) and the condom broke. I didn't take plan b because I felt like it messed my period up so much the first time and didn't know if it was bad to take it twice in a month and so close together. I've been avoiding birth control because I had a really bad experience with the IUD and also the pill. I am usually really safe about sex because I don't want children right now. I'm currently not freaking out or anything but I don't know if I should be. I guess my question is, how do you know If plan b actually worked? I was assuming when you're spotting that's how you know you aren't pregnant... But then again, what about the most recent time when the condom broke? How soon is too soon to take a test? My period has been so messed up that I honestly don't even know when I'm supposed to start it again. So how will I know if it's late or not?