hi there! roughly 3 weeks ago i (m) had unprotected insertive anal sex with another man. Penetration was brief, less than one minute. He is on daily PrEP, and i am not. Two days before the encounter, he had unprotected sex with another person who said they were sri free/negative. My sexual partner informed me that he got tested 13 days after the encounter with the person before me, resulting in a negative RNA as well as a negative 4th generation HIV test. I also tested negative with a 4th generation hiv test at 21 days post exposure. With the research i have done, a negative 4th gen test at 21 days is very reliable. Given that the partner i slept with had a negative rna and 4th gen test after the encounter with the partner before me, would you recommend I test again? He takes his PrEP without fail, and has been on it for over two years. I also tested negative at 14 days, but wanted to test at 21 days to be more confident. I understand this is a unique experience, so thank you for the guidance! 

Welcome to the forum.---

Thank you so much! I had been looking for solid information about the time of exposure to becoming contagious, so that helped immensely. The partner i was with is seemingly anxious about his results and is wanting to test again in a week (27/28 days after his exposure). I told him that the RNA with the combo ag/ab was accurate given the timeline of the RNA test. He said he was concerned that his prep use would skew his results. Am I correct in reassuring him that his RNA test is conclusive? I would just like to share this info with him to help quell his own anxiety.  thank you so much again! 

I would say your partner's PrEP makes testing unnecessary, and so do your negative test results -- more than worrying about affecting the reliability of the test. There is no chance either of you has HIV, or had it at the time of your mutual exposure. In any case, there have been few if any studies on test interpretation while on PrEP, but most experts believe negative test results remain valid. If your partner remains unconvinced, it would make sense for him to follow the advice of whoever prescribed his PrEP, who likely has more experience with it than we do.---
---
---

thank you very much for your help and the work you do! i feel confident that i can move on. also got prescribed PrEP today so i now have the courage to start taking it after this reassurance from you! thanks again. 

Thanks for the thanks. I'm glad to have helped.---