Should I be paranoid?

Ok, so last week (Jan 5) I had sex with my boyfriend for about 5 minuets and we realized the condom broke. He did cum inside of me so out of panic we immediately went to the store and bought Plan B. I took it maybe an hour after it happened. On Thursday I had what looked like spotting and what looked like my body was telling me ok you should start your period tomorrow. But it didn’t start and now I’m freaking myself out. In December (before we were even together) I had two periods. One on December 5 that was normal 6-7 days and then again December 22 for about 5 days. So my cycle was already weird to begin with and now I can’t figure out when my period should come. And I’m stressing out that the pill didn’t work. What should I do now?