Brief Answer:
The chance you got the infection is very low.

Detailed Answer:
Hello!
I read carefully your query and understand your concern.

A good rule for dating is to assume that sexual partners are infected unless known to be otherwise.So in this case let assume that the girl was HIV positive.
In this case there was an exposure to HIV virus (assumed) because when your penis came in contact with her blood,even you had no wounds in penis,the blood might have contact with your fluids.This is a very low chance but it is better to take it in count.

The actual chance of becoming infected with HIV during a single sexual experience — even with a partner who is known to be HIV-positive — is rather low
The chance of infection increases with repeated acts of intercourse (more exposure to the virus), yet the risk of transmission in any one sexual episode differs. For instance, transmission is more likely when there is an increased amount of virus in genital fluids or blood (a high viral load) than when the viral load is lower. Also, studies have shown that infection rates are generally higher for male-to-male transmission but lower for female-to-male transmission.

It might take repeated exposures to HIV before someone becomes infected. It means that the transmission rate of HIV is not 100 percent; a person having sex with an HIV-positive individual might get the virus after one sexual episode, after two, after ten, a hundred, or possibly never.

It is important to emphasize that a person could become infected from having unprotected sex once or a person could have unprotected sex many times and not become infected, regardless of how low or high the risk per exposure is.

Since you didn't have an vaginal intercourse with this girl, the exposure lasted just a second and all the facts I mentioned above,the chance that you got HIV is very very low.
There is no evidence that the virus can be transmitted by oral sex,so the risk for you is very low.

No matter how long I tell you that the chance for you to be infected is very low and beyond all statistic,no one can tell you that this is impossible and the probability is zero.
The only way to know if you are HIV-infected is to undergo a simple test which can be performed on blood or saliva with results available within minutes of testing.
This is the only way so you can rest your mind and not worry anymore.

Hope I was able to help you.If you have further questions please feel free to write me.I will be happy to help.
Wish you good luck and please be careful,always protect yourself.

Dr.Rovena

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