I had another 4th gen HIV test yesterday at the 33rd day mark and it came back negative but I understand that it's not conclusive yet. I read that at one point in time, 28 days was considered conclusive but then the CDC decided it should be 45 based on a few cases. I also read that you have never seen or heard of a negative test at 4 weeks that turned positive later on. 

Now, (1) is it true that from our scientific understanding of HIV, a 4th gen should be conclusive by 4 weeks? And (2) is it correct to say that when it was first decided that 4 weeks is conclusive it was based on studies and scientific research and then, based only on reports with no scientific studies, it was extended to 6 weeks? And (3) is it correct to assume that there were numerous scientific studies and research that came to the conclusion that 4 weeks is conclusive but there were only a few reports that advised 6 weeks? 

Thank you Drs

The change from 4 weeks to 45 days isn't very recent; it came five years ago, based on a review paper published in December 2017. There were scientifc studies before then, but additional ones were published in the 2010s that justified CDC (and this forum) modifying the advice to 45 days (which on this forum we often round off to 6 weeks). Personally, I am unaware of any cases that tested negative with the AgAb (4th generation) blood tests 4 weeks after exposure and positive later.

Your final test result will be negative. If you remain nervous as you wait, I suggest you go back and carefully re-read all of our previous discussions. You really should not be worried at all.

Best wishes--  HHH, MD