Hello, had 4 th generation test 21,25,28,31 and 35 days after exposure. how accurate are they? and second question the index on the tests has a variation from 0,13 to 0,23. my last was 0,23 and was never so high.what has this index to say? thks?

Your negative results day 25 and afterward were 99% conclusive, but to be 100% certain have a final AgAb (4th generation) test after 45 days. The variable index no. on repeat tests means nothing as long as the value is below the neg/pos cut-off (usually 0.9). All results below that are equally negative. The same specimen tested 10 times would give 10 different numbers anywhere from 0.1 to 0.8.