Could a htlv and hiv infection at the same time cause delay in hiv seroconversion? what about hepatitis c? hep c rna test negative at 4 months post exposure. hiv-1 rna and ab/ag negative at 4 months as well?

Given the results you presented, you do not have HIV or Hep C infection. Visit this site for HIV window period and explore the same site for Hep C window period. HIV test window periods https://www.cdc.gov/hiv/basics/hiv-testing/test-types.html

There are no medical conditions (or medications) that cause unreliable or delayed HIV AgAb test results. None: it's an urban myth! Although some rreports suggest hepatitis C may do so, that's rare if it happens at all -- and your test results show you don't have hep C anyway. Your HIV AgAb test proves you do not have HIV: no further worry, and no neeed for additional testing.