Plan B

I had sex for the first time w my bf the day before I was supposed to start my period and after we realized the condom broke but idk if he came inside me. I took plan b 20 mins after and it's been a week without getting my period. I had spotting the day I took it and a few days after too. Is that normal cause I am small and 16 so maybe the dosage was strong and had a huge effect on me. I also don't think I was ovulating but my periods tend to be irregular. I'm also stressing a lot pls help