Are There Any Chances That HIV PCR Qualitative Tests Results Are Wrong Because I Was On PEP?

I had unprotected oral sex on 18 June. Doctor started me on PEP on 20 June (within 48 hours of exposure). I was prescribed - Tavin EM. Just one drug. Post that, I have taken HIV PCR Qualitative tests (6, 13, 18 and 31 days post exposure). All negative. I have also fully taken PEP with complete adherence. Are there any chances that these qualitative test results are wrong because I was on PEP? What do you recommend?