Can i consider my negative hiv 4th generation test result at 90 days after potential exposure conclusive?

Yes unless ....: These test for HIV antibodies and p24 antigen simultaneously. ... A negative result on a fourth generation test performed at 4 weeks post-exposure is highly likely to exclude HIV infection. A further test at 8 weeks post-exposure need only be considered following an event assessed as carrying a high risk of infection. If a second contact occurred during this time period another test may be needed