Welcome to the forum.
You've been quite busy the past 4 months on the HIV community and international forums. You seem to have had difficulty understanding (or believing?) the generally reassuring comments and advice you received there.
The basic fact is that in the US, the risk of catching HIV from any single exposure to a female sex worker is very, very low. The large majority of such women do not have HIV (mostly under 1 chance in 1,000), and if a woman has HIV, the average transmission risk for a single epsiode of unprotected vaginal sex is around 1 in 2,000. Therefore, we can calculate a rough risk of 1 in 2 million for the event you describe above. This is why experts don't even recommend HIV testing after any single exposure, except in special circumstances, e.g. unprotected sex with a partner known to have HIV. With your apparent sexual lifestyle, I would encourage you to ignore individual sexual exposures and just plan on routine testing for HIV (and other STDs) from time to time, like once a year or so.
But I imagine that, having started down the testing pathway, you're going to want to continue until you have a conclusive result. The oral fluids test is the slowest of all standard HIV tests to become positive. The standard ("3rd generation") blood antibody tests are virtually always positive within 6 weeks, but oral fluids require 3 months for a conclusive result. Your negative result at 25 days isn't useless, though; it's probably around 70-80% reliable.
PCR testing is not recommended in such low risk situations. My advice for a definitive test is that you wait another 3 days, i.e. to the 4 week mark, and then have a duo (also called "combi" or "4th generation") test for both HIV antibody and p24 antigen. That test is 100% conclusive at 4 weeks.
Below are links to two threads that discuss the times to conclusive HIV test results, depending on the specific test (or combination of tests), including why testing earlier than 3 months is usually conclusive, despite official advice that says 3 months is necessary.
I hope this has helped. Best wishes-- HHH, MD