You are correct that a few seconds of unprotected vaginal sex IS low risk, but NOT NO RISK.
Bottom line remains that you had a risk, regardless of how low it may have been, but I am certainly NOT qualified to assess that risk and advise you FOR or AGAINST beginning PEP treatment. Only a doctor can make that call.
I feel confident you know the window period to begin PEP is 72 hours.
You stated that you went to a clinic in which you were advise to "at least think about PEP." I believe that is pretty sound advice and agree with them. You have stated that you are "cynical" about medical practitioners in general in that part of the world. Since I am giving you the same advice, do you remain cynical?
That the CSW did not have any condoms I would find a bit disconcerting, as, apparently, you did
I personally recommend NEVER taking the word of ANYONE regarding their HIV status. The CSW you were with stated she "is clean and gets tested." That's all well and good if you believe it, but the other question is when was the LAST time she was tested? She may very well have been clean of HIV and STD's, but how many customers did she have between that test and your encounter with her? How many of those customers didn't care that she didn't insist on a condom? How many of those customers might not have been "clean?"
You say you are "stressed about it but I still think the odds are pretty long."
While statistics run in your favor, and I, too, believe the risk was low, I will be redundant..........low risk does NOT equal no risk.
Is it worth the gamble to you?
You're holding the dice and the clock is ticking..............
I wish you the very best outcome
RubyWitch