Decisions about PEP are best made by local health care providers who understand the details of local HIV epidemiology, such as the frequency of infection in sex workers. However, I see no need for PEP. First, even if your sex work partner has HIV, the odds of transmission from a single episode of unprotected vaginal sex are around one chance in 2,500. And with her negative Oraquick test, there is almost no chance she has HIV. Your risk is low enough that you really don't even need HIV testing -- although of course it would be understandable if you decide to test in a few weeks, for reassurance despite the zero risk involved. You also might want to consider testing for common STDs, i.e. a urine gonorrhea/chlamydia test (valid 4-5 days after exposure) and a blood test for syphilis in a few weeks -- although the risks of these also are very low, assuming no symptoms like urethral discharge, painful urination, or penile sores.