Welcome to our Forum. As I reflect on your question, you are absolutely right- most of the questions about masturbation and touching are from a male perspective. I can tell you however that the biology of masturbation and touching is the same for members of both sexes. There is not risk to you of getting an STD from a male who touches or masturbates your genitals, even if he has touched himself or has genital secretions on his hand at the time he does. You do not need testing or to be concerned. I am confident that your pelvic and back pain is not related to the event you describe although stress, whether from this or something else certainly could do it.
I hope my comment helps in some small way to relieve your stress related to this event. Take care. EWH
Thank you. You have eased my mind greatly! I appreciate your time.