You should not have sex with anyone until BOTH of you have gotten tested and have seen the current results. This is a thing. This is what people do (or should do) these days. This is part of the term “safe sex”.
If your fellow gets angry, or refuses to have the test, say, “Next!”
Saying one is clean means absolutely nothing. Better to be safe.
You should never be afraid to discuss sex with the person you are going to have sex with. Here’s what you say, “Rob, I really like you a lot, and I’m very interested in moving our relationship to the next level. It’s very important to me, and my health, and your health, and our communication, for both of us to get tested for AIDS. I hope you agree. What date shall we both get tested, I’m thinking next Tuesday.
Before you have the conversation, contact the testing site, and ask when they have appointments. Let them know that you’d like you and your boyfriend to come in at the same time. It makes sense to go together, and to use the same clinic, that way, you and he are showing your commitment (not to pledge your undying love, that might come later) to being responsible. So when you bring up the subject, you can tell your boyfriend that such and such a clinic has walk ins on Tuesdays (or whatever you find out) and then see how he reacts.
If he gets mad, or tries to stall, or has an excuse for why he can’t, or tries to get you to have sex with him, before you’ve been tested, you need to rethink the whole relationship.