The reason it's impossible to give you odds is that one very important factor is missing in the equation - we don't know if she is HIV+ or HIV-. If she is positive, then experts state a risk of around 1/2000 encounters. And, and STD can only increase the risk *if* she is HIV+.
The good news is that the chances of having an encounter, just by chance, with someone who is HIV+ is very low. So, you'd want to multiply the chances of having had sex with someone who is HIV+ by the chances of getting HIV from a single encounter - that is going to be a VERY low number, indeed.
There is some evidence that having an std increases your risk of getting hiv. That doesn't mean you did or you will so try not to panic. You had a risk by having unprotected sex so you will have to wait until 28 days to take a 4th generation Duo test. It's hard to wait but that's all you can do. The good news is that a one time event makes the chances less and that it was a regular girl rather than a csw, the chances are also lower. The RNA is a really good predictor and don't think you will end up positive, but you should still test with the Duo at 28 days. Sorry.