PEP is often reserved for cases where one partner is likely to be HIV+, and the risk was high. That is not the case for you. Any CSW who wants to use a condom is protecting themselves from you, not the other way around. Also, a few seconds of unprotected penetration is really not a risk - consider that, for a full-on session of unprotected vaginal sex with a known HIV+ partner, the risk is 0.04% to the male. In other words, a 99.96% chance of not contracting HIV.
Multiply this risk by the low chance that you encountered a person who is HIV+, since the vast majority of people are not, and you're looking at incredibly low odds.
I don't advise people who have had a legitimate risk event whether to take PEP or not, as that's a decision best left to the individual and their doctor, but if you asked me if I would take it in this situation? Absolutely not. The risk of side effects from the meds outweigh the risk by a longshot, for me.
1st of all : no doctors here , just volunteers following protocol of forum as guided by doctors in the forum before
2nd : if she refused to continue after condom rupture , this means she is worried and she is mostly hiv negative
3rd: you have very, very low risk exposure
4th : Pep is prescribed in case of high risk exposure with hiv positive person, but to continue or to stop is your decision. You can discuss it again with the physician who presribed.