Hi there, I do not have the possiblity to talk to any doctor about my problem so please answer my question....
About a month ago I made a mistake and let an stranger finger me while I was in his car(I am a girl) I was fool enough to did not check his hand whether he has any cut or wound or bleeding on his hand, am I at risk of HIV?
As I read the I'm curious to know the 'mistake' part. You said you 'let' this happen, but did it happen because you wanted to enjoy an intimate encounter with another person, or because you were coerced? I understand that an experience like this has the potential to simultaneously pleasurable as well as terrifying. As a gay man who had a lot of fingers put inside of him during some of the darkest days of the AIDS epidemic in the early 1990s, I can promise you I've done my due diligence on this issue.
Fortunately there is no risk of HIV being transmitted under these circumstances. HIV must be transmitted directly from the mucous membranes of one human into the mucous membranes of another. The virus dies immediately upon contact with the air and cannot be transmitted casually through hugging, kissing, fingering, rubbing genitals, sharing toilets, etc.
Nothing I say here, however, will assuage your fears as much as an actual test. When in doubt, it is wise for any sexually active adult to get routinely tested for STIs. When doing so, please make sure they are doing "three site testing," meaning they swab your throat, your vagina, and/or take urine. If you ever have receptive anal sex, then it's important you receive a rectal swab as well. The reason for this is that many STIs are 'localized', meaning gonorrhea in your throat would not show up in a urine sample.
Remember even when you're in someone's car, you always have a right to say 'no' to any touch or activity that you are not comfortable doing. Consent is important.
To learn more about HIV is and is not transmitted, please feel free to visit our resource page here: http://www.thebody.com/content/30024/hiv-transmission.html . I hope this information allows you to relax, get tested, and enjoy the kinds of experiences you wish to enjoy. Have fun!