I had an hiv antibody/antigen (ag/ab) test 45 days after my last dose of pep and i tested negative. is this result conclusive? is it a true negative? some say 3 months but that most people, if theyre positive, will test positive at 6 weeks?

There has been no precise research on how long positive test results may be delayed following PEP. As you have found, most experts believe 6 weeks is sufficient, but others still advise testing at 3 months. But all experts agree your negative result at 45 days is very reliable; if you test later, you can expect another negative result. Good luck.