Hi StillWorried, Sorry for the delay in getting back to you. The BioSURE HIV self-test was launched in 2015 and has been through numerous clinical trials and tests to determine the accuracy of the window period. The vast majority of people produce antibodies, but a small percentage do not produce antibodies. Regardless, every person whether they produce antibodies or not, is detectable. It just depends on the method of testing and/or the length of the window period for testing. The tests that you have performed all outside of the window period are conclusive results and if you were positive, your result would have been detectable. I hope this helps to put your mind at rest, remember not everything you read online is correct. Kindest regards, Becky