Additional info of my first question. The exposure was unprotected viginal sex with sex worker of unknown hiv status.
As ANM said, combo is conclusive after 28 days. So you need to stop and move on from HIV fear.
My advise, always use condoms for anal and vaginal sex.
Yes, you were given a 4th Generation HIV test that looks for p24 antigen protein and antibody reactions in tandem.
This test was done using CMIA technology, which is FDA approved. This test is conclusive at 28 days or later from the date of exposure.
You have conclusively tested negative, you do not need any further testing.
Testing out beyond 6 weeks is outdated unless you live in remote places of Zambia or Mozambique etc. which might not have access to II or higher generation of HIV tests, it is certainly not the case even in those parts of the world.
I would suggest you to work with a counselor who would is up to date with HIV information.