hi, 3 weeks back I had & given oral sex with my girl friend. She said she never had sex before. But I am not sure. Please tell me, am I at risk? and whether I have to go for the HIV test?
The CDC has documented only a few cases of HIV transmission to a person performing oral sex on a woman. This is the best evidence that the risk of transmission through cunnilingus is very low. There is no evidence that people get infected when receiving oral sex (that is, your risk is only theoretical when an HIV infected person puts their mouth on your genitals).
The risk of HIV transmission through oral sex is low when compared to unprotected vaginal and anal sex. The reasons for this, in part, have to do with biological differences: simply put, HIV seems to have a more difficult time causing infection when introduced to the mucous membranes of the mouth (saliva may provide additional protection and the cells in the mouth may not be as prone to infection). Secondly, the concentrations of HIV in vaginal secretions seem much lower than the concentrations of HIV in cervical secretions and menstrual blood. When performing oral sex on a female, the mouth is more likely to come into contact with vaginal secretions. Some sources suggest that vaginal fluids dilute the more infectious fluid, decreasing the chances of transmission to someone's mouth.
It is important that you do not perform unprotected oral sex on a woman when she is menstruating (blood has a much higher concentration of HIV), and if you are experiencing any problems with your oral health (sores, abrasions, inflammation). If you would like to decrease the risk of transmission even further, you can use a latex barrier--like a dental dam or a condom cut into a square--between your partner's vagina and your mouth.
For more about transmission through oral sex, see the CDC's fact sheet on oral transmission.