Help please!

Okay so I have a problem. I had unprotected sex Monday. He said he would pull out and he did, and then put it back in (sorry). I wasn’t on birth control for about 4 months and I just started it again on a random day and missed a few and also don’t take it consistently with being the same time everyday. My boobs are super sore and I have right side pain, is that ovulation and could I get pregnant? This guy wants me to take plan b because he thinks i will become pregnant. I want your bed advise for me. I’m in a pickle and I have no idea what I should do. Thank you!