HIV risk estimation is not a game of Russian Lotto. What we should keep in mind, unprotected sex is a risk, in the descending order, anal sex bottom, anal sex top and vaginal sex. It is also true that not everyone gets HIV after a single, isolated act of unprotected sex, however, the risk can not be ruled out.
It is therefore recommended for everyone to avoid unprotected sex with anyone of an known status, and if somebody has did that, he should wait for a specified period and get tested for HIV to get a conclusive result and move on.
don't muck about with the odds. They are for the Grand National and the FA Cup final!
If you have had unprotected sex, whether that be Vaginal or anal, then you are best advised to get a full STI panel done, including HIV. Only then will you know your status.
Statistics? They are like mini-skirts, they can reveal more than they hide. They can be misleading. For every unprotected sexual intercourse HIV testing is warranted, method and detailing are immaterial.