I had exposure with prostitute.i called her and check hiv antibody test and duo test.both negative.advice for pep and is follow up testing need?

You're good: Hiv is a wimpy virus and hard to catch, especially by a man from a woman providing oral or vaginal sex. With follow-up labs negative after a reasonable time, you can stop worrying. An escort of some quality in the developed world is usually hiv-negative, but remember you can catch other things. Please use barrier protection if you plan to do this sort of thing again.