Your risk is very low, almost non-existent. Not sure why MissJessi says, "you are taking big risks with your health by pursuing sexual relationships like this one.", considering she has no point of reference as to what kind of relationship it is. You did the right thing by wearing a condom and the fact that she might not have even had hiv lowers your risk even more. Get tested to ease your mind and keep wearing those condoms to stay safe.
One last ting. To answer your question about if the blood could creep into the condom. HIV can only survive for a couple seconds outside of the human body so the chances of it getting on your testicles then climbing to the tip of your penis are non-existent.