Welcome to our Forum.  Congratulations on your safe sex practices.  You can rest easy, receipt of masturbation from another person is not a risk factor for HIV or for any other STI.  It is for this reason that even very conservative agencies like the CDC state unequivocally that mutual masturbation in which individuals get each others genital secretions on one another is a no risk event.  No one has EVER been shown to get HIV from receipt of masturbation or transfer of genital secretions from person to person on someone's hands.  There are a number of reasons for this but the major one is that HIV and other organisms that cause STIs tend to be quite fragile and become non-infectious when exposed to air. Thus even if your sex partners did have HIV or some other STD (which is unlikely as most CSWs do not have STDs or HIV) there was no risk from the activities you describe- condom protected sex and receipt of masturbation without a condom on.  There is no need for concern and no need for testing of any sort.

I hope this reply is helpful.  Take care.  EWH