If you are using condoms every time and correctly and if it s only for oral sex, you are not at risk for infection. If you were having vaginal or anal sex, the odds change because there is a greater risk for condom failure every time you have sex. Measure your risk by looking at the facts. Try not to confuse yourself with abstract scientific concepts. Questions like yours are common.
Some people feel guilty about having sex with prostitutes.
For some people, it is their only sexual outlet. For others, it can be secretive and shameful. Sometimes shame or guilt takes shape as HIV anxiety. If this sounds familiar, finding others to talk to about your experience can help. I do not see a need for you to be HIV tested in these circumstances.