How should I react

So my bf and I have been together for 7 months and we don’t plan to have sex yet. But we do talk about it a lot. One thing keeps crossing my mind tho. While I know that both me and him are clean. I heard it is possible to get STIs even if both are clean before sex. I will be talking with my doctor about this when I go to see her. But it made me think more about using condoms. I tried talking to him about it. He said that he really doesn’t want to use them but didn’t give the clearest answer. I told him that if we end up having sex before we are 18 then I will only have sex with a condom because I don’t want to risk getting pregnant. He agreed on this. I tried telling him I don’t want to do anal without using a condom because either of us could get an infection but he basically disagreed and we will be fine as long as we clean ourselves before and after. Should I just let it be?