Assume the test is 90% sensitive and, based on the FDA, is 99.98% specific (prob.
of testing negative if not infected). This gives a negative predictive
value (prob. of not being infected when testing negative) of 99.9997%. In other words, there's about a 1 in 400,000 chance of being infected based on these (conservative) assumptions. Does this seem right?
I'm wondering if this sufficient proof or whether I should test again. It is 8 weeks.