At 3 weeks the standard antibody test would detect over 2/3 of recent infections and the DUO test would detect more but not all. A negative test would provide additonal evidence that you did not get HIV but would not be "definitive". In your circumstance however this would be further very strong evidence that you did not get HIV. EWH
Thank you that does help, although I am just wondering If I was to get the test done after three weeks would that be ok?
Welcome to the Forum. I'm sorry that you are having these problems. I hope that the comments I am about to make will be helpful. Your risk from a single encounter is low. Very few heterosexual men (less than 0.1%) of heterosexual men have HIV unless they are IV drug users. Further, even if your partner ha HIV (most unlikely, as I said,) the risk of getting HIV from a single unprotected encounter is less than 1 in 1000.
I realize however that may not keep you from wondering if your are "the 1 in a million". If you can find this fellow and have him tested, you will know. He could only have HIV if he had a positive test at this time and if his test is negative, you could not have gotten HIV from him. If you cannot follow this route, at 4 weeks an HIV antibody test would detect over 90% of persons with recently acquired HIV and in your situation this would be very strong evidence, when considered along with the odds, that you did not get HIV. If you are in Australia, I believe combined HIV p-24 antigen./ HIV antibody tests (also called “DUO” tests) are available which provide definitive answers at 4 weeks. Antibody tests performed at 8 weeks are definitive.
I hope this helps. Your risk of infection is quite low. EWH