Scared shitless!

So last night me and my new bf hooked up it was great until he said he was gonna… you know, I told him to do it on me but a couple seconds later it was inside me. I’ve missed a couple of my birth control pills and taken a couple late and have also been in some antibiotics that could screw it up. So to stay the least I’m scared shitless… what do you guys think? I’m 16 years old do you think I’m gonna get pregnant?! J want a baby but not at this stage in my life! And the plan b pill isn’t an option for me because of some heart issues I have! Someone help!!!