I had an encounter with another man on the evening of June 9th.I performed oral sex on him (no ejaculate, but maybe precum)we made out, he humped me, no penetration, and he touched my anus with his finger. I took prep on demand, with one extra dose, so 2 on June 9 a few hours before meeting him, and then -1-1-1, final dose on June 12. I have thought of “what if” his finger had cum on it and he rubbed my anus that could have had a cut on it, or his penis had pre cum on the tip and he rubbed my anus. I took a hospital lab, blood drawn fourth gen test 30 days after this exposure (tested on July 9th), and it came back negative. My primary care doctor, and a nurse practitioner at a local sex health clinic both said No further testing is needed. I was feeling a little better about this after reading on this forum and seeing that the 4th gen test is 98% reliable at 30 days, but now I am nervous again and I am concerned the 2-1-1-1 prep could have effected my 30 day results

Welcome to the Forum.  Thanks for your questions.  I'll be glad to comment.  The encounter you describe was low risk for HIV - you do not know whether your partner had untreated HIV or not and statistically it is unlikey (in the future, I would suggest asking partners about their status) and the risk of infection from performing oral sex on an untreated infected person is less than 1 infection per 10,000 sex acts, on average.  There is no risk for infection from making out, being "humped" without penetration or receipt of anal fingering (masturbation). Your use of PrEP on demand lowers your risk for infection still more.  PrEP on demand, like standard PrEP rarely fails and, as result there are few data on whether it might slow tests becoming positive on those rare instances when it fails.  While I suppose that theoretically this might be the case, those failures that have occurred have been detected within the standard testing window (6 weeks) following an encounter.  Based on all of this, I agree with your doctor and the NP you spoke with.  I too see no medical need for further testing.  EWH---

Your anxiety is showing; postnasal drip is not a sign of HIV and, if it were, your test would have been positive.---

You were right, Doctor. I just took an additional Fourth gen test, now 8 weeks post exposure, and 7.5 weeks after my last dose of prep on demand, and it was negative. Is it time to put this behind me? Thank you for your help. 

Thanks for your thanks.  I’m glad I could help.  Your results are conclusive.  Time to move forward without concern.  The thread be closed now.  Take care.  EWH---