Ditto the above reply. You didn't have a low risk, you had NO risk. Anxiety860 explained the only ways you could ever be at risk for HIV. If you haven't done those things, you don't have an HIV concern.
The problem lies with the fact that due to a lot of fear based education, and a lot of misinformation, many people have very overinflated views about the real risks associated with HIV. Despite what people think. HIV is actually pretty rare, and is very hard to get.