It's extremely unlikely that your boyfriend, given he is heterosexual and has never injected drugs, has HIV. The chances of him having HIV are very, very, very low. If you want my opinion, he is probably avoiding you because he's nervous of a possible pregnancy occurring. For boys to start being closed off and start avoiding a girl after an experience like that can be expected.
That being said, if you did experience condom breakage, then it's your responsibility to test for STDs. Your chances from a one time exposure such as yours are around 1 in 1,000, and even that is probably too high. Test at 3 months for a conclusive result and try not to worry so much in the meantime. I wish you the best of luck.
Only way to know is to test. 6-8 weeks will give a good indication and then 3 months will be conclusive.