So many reasons but I can’t tell which one it is!

At the beginning of June I slept with a guy and my stupid self didn’t think to use a condom. He ended up pulling out very last second and I’m sure there was some inside of me. I wiped what I could out, but I don’t think I got it all. A week later I slept with my now boyfriend and got scared of Precum and took a plan b the next day. I also started birth control two days before the plan b. I’m now 6 days late for my period and my breast hurt to simply run my finger across them. I have no clue which one is causing me to be late! Help!