Hi Stillunsure123, It depends on whether it would help to put your mind at rest by doing a fourth generation test. The main benefits of using a fourth generation test is the shorter window period (but given the time since your last exposure, this will not make a difference) and the fact that these tests are performed by healthcare professionals - self testing is not for everyone and some people may feel more comfortable or reliant on their result if it is performed by a professional. There is not much difference in accuracy between our test (2nd gen) and a 4th gen test, our test would have been able to accurately detect the antibodies in your blood. The two BioSURE tests that you have performed are well outside of the window period, so your results are conclusive. Usually when a person tests positive after an exposure that was over a year ago, the test line is very dark and very visible so I would not be worried about misreading your negative result as the test line would have likely been very visible. Your negative results are accurate and conclusive and there should be no need to retest unless it may help to put your mind at rest, but I would try to put this behind you and move on if possible. Kindest regards, Becky