Hi Worked up, Your negative results at 103, 287 and 313 days are extremely reliable. Oral sex is low risk due to the limited transmission routes. The clinical specificity which is explained by the percentage of correct negative results (1 in 1000) does not necessarily mean that every 1 in 1000 tests will give a false negative result but from performance studies, the test was proven to be able to specifically detect 999 out of 1,000 negative results correctly. 2 false negative results (outside of the window period) are extremely rare but 3 false negative results I would say are near to impossible. I hope this helps to put your mind at rest, if you need any further information or clarification please let me know below. Thank you. Kindest regards, Becky