Chest pain and breathing problems have nothing to do with HIV. That sounds like severe anxiety, and I would see your doctor about that.
Unless you were highly intoxicated, you would know if the condom broke, or if you pulled your penis out and didn't have a condom on. If you are concerned, do as Chima stated and get a 4th or 5th generation test 28 days (or more) after the event. RNA tests are extremely expensive, and they aren't intended for primary diagnosis. They should only be used in those who had a clear, high-risk event, which you did not. At the very worst case, if your condom came off, you had LESS THAN 0.1% risk.
Symptoms are not used to diagnose HIV. It sounds like you're not sure if you had a risk or not. Therefore, you should get a 4th generation ag/ab test done anytime 28 days or more after exposure for a conclusive result.