Thank you very much Dr. Handsfield, your advice is very compelling.
Do you have a view on the better safe than sorry argument that even if my chances are 1/ several million, is there any downside in taking the PEP now that I have picked it up?
Thanks again.
Welcome. However, this question belongs in the HIV Prevention and Safe Sex Forum; this forum is for non-HIV STD questions. Accordingly, there won't be an opportunity for follow-up discussion.
It is statistically very unlikely a partner like yours has HIV, especially in a west coast city like San Francisco, as suggested by your username -- no higher than 1 chance in 1,000. And based on the other detaisl you know about her, I suspect it is far less likely than that. Second, even if she had HIV, the risk of transmission from a single vaginal sex exposure is estimated at around one chance in 2,000. Combininb the two risks, the chance you caught HIV is 1 in several million, i.e. zero for practical purposes.
Therefore, I agree with the advice from your doctor: no PEP. In fact, I wouldn't even recommend HIV testing after such an exposure, except if you feel you need the additional reassurance of a negative test result.
Even better, rather than waiting a few weeks to be tested yourself, why not contact your partner and suggest the two of you go together for HIV testing (as well as other STDs) right now? You may find she is just as nervous as you are; after all, the overall risk of HIV and other STDs is much higher for women in this situation than for men. If both of you have negative test results, you both will know for sure there was no risk for either of you.
I hope this has helped. Best wishes-- HHH, MD