Straight sex is irrelevant. Hiv is not a "gay" disease, despite what you've heard. Drug use is also somewhat irrelevant, although it can be contracted that way. Hiv is sexually transmitted. Straight people catch it every single day.
It is a good idea to get yourself tested not only for hiv, but for other std's as well. If you have something, you need to know so you can receive treatment, and refrain from possibly spreading it to someone else. Go get tested, and remember to use protection in the future. Good luck.