What should I do????

Me and my boyfriend are 16 and have been together for 7 months. We've had sex around 4 times, I'm not on birth control and don't want to be for a while. He always wears a condom and pulls out before cumming. I've just been feeling so much stress and anxiety that I could be pregnant and it wont go away. He tells me I'm fine and that he's 100% positive that I'm not pregnant. I feel like I'm considering stopping having sex until I'm out of school or could get on the pill. I don't know if this is fair on my boy. What should I do????