Hello Doctor, I had an exposure where condom broke while doing anal intercourse (quite brief, may be 3 thrusts unprotected) I was put on pep after 48 hours (2 days). One day after 28 days of PEP completion, I took 4th generation test which come back Negative (30 days post exposure, 1 day post PEP). I was advised to go back and test in the next 8 weeks. 1. However, I would like to know that is my test immediately after finishing PEP a good indicator. 2. Have you ever experience someone who tested negative after PEP completion but positive in the next 2 months without further exposure? 3. I read a lot information online. Some say that PEP can delay seroconversion so test immediately after PEP is not accurate. Some say that if PEP failed, the antibody still can be produced while on PEP and the test after PEP completion should show positive in this case. Which one is true? Thank you so much in advance.