Welcome to the Forum.  I'm pleased that you have found our comments and advice helpful.  With regard to your first question, a statement that a partner is "clean" is a bit reassuring but perhaps not as reassuring as a comment telling you that she is checked regularly and does not have infection.  As a commercial sex worker however, STIs, including HIV are occupational hazards and many CSWs 9particularly those working in higher class settings such as hotels or brothels) do make the effort to get themselves checked on a regular basis.  As a generality the prevalence of HIV among CSWs in Dubai (we get many questions from persons who have had partners in Dubai) is low.  

I agree with your sense that if she offered unprotected sex to you, she is likely to do this with other partner/clients as well.

Finally, frottage is safe sex.  Even if your partner was having her period, the chance of you getting HIV from frottage with a partner who is infected and having her period is virtually zero and should not be a concern. If I were you, I would not worry and would not feel the need for testing.  I am not aware of any data that suggest that the presence of menses changes the risk for HIV infection with any specific sex act.

I hope these comments are helpful to you.  I congratulate you on your commitment to safe sex and encourage you to continue to do so,.  EWH