Third Generation of HIV tests only looks for the body's response to HIV infection - Antibodies.
Fourth Generation of HIV tests are advance, they look for antibodies and also a core viral protein called - p24 antigen.
Your test was a fourth generation HIV test and you have tested conclusively negative.
Your exposure would be good to have. If could share that please.
But in general, if you took a duo test, that is a 4th generation test. 4 weeks after your exposure, a duo test is 98% accurate.
What was your risk, oral, anal or vaginal and did you use condom?