Last Wed Night I had unprotected vaginal sex with a friend of mine who is 49 and white. It was very brief and only lasted two minutes. I went to test for trich, gono, and chylamdia today 108 hours after my exposure. Right now I have no symtpoms. 

My questions are:

How likely will the test results be accurate?

How high was my risk?

Is only waiting 45-50 minutes before I urinated okay?

If my results are negative, can I continue relations with my regular partner?

In general, STI/HIV testing is not recommended after any single exposure unless one's partner is known to be infected or at particularly high risk. And statistically, people almost never are infected by one's friends. I'd put the odds you acquired any STI at under one chance in thousands. You can expect the tests already done to be negative. Time since last urination is now known to make no difference in reliability of testing for gonorrhea or chlamydia, and probably has no effect on trichomonas testing either. Once you get the negative results, you can safely continue sex with your regular partner.

You don't mention the biggies, syphilis and HIV. But the odds you caught either of them is well under one in several million. I don't advise testing for either one, but if you feel you need the reassurance of negative test results, you can have blood tests for them 6 weeks after the exposure -- but you shouldn't hold off on sex at home in the meantime.

Let me know if anything isn't clear.

HHH, MD

What do you think my risk is for genital herpes? I don't know that she has anything but of course I get what if thoughts.  How many days after sex should I be in the clear ?