Am sorry to say that Dr. but you still living in the 80's.
PCR DNA can detect the virus more earlier than the three month window period, it is not conclusive but at least a step to expect what is coming next. I had three very qualified doctors and they all agreed that a DNA PCR on day 28 is over 90% accurate, combined with a
DUO ag/ab test on day 42 that would be more than 99.9% accurate. and the 0.1% is not for false negatives it is actually for false positive.
Am not a doctor, but this is my experience with the very qualified doctors i came across from UK