If you were checking out this site which is moderated for accuracy, you'd read that receiving fellatio is zero risk. As it involves air and saliva, both of which inactivate the virus, it is not a risk for HIV. The only way adults get HIV in the real world is to have unprotected vaginal or anal penetrating sex or share IV drug needles. Even if she is bleeding, what you describe is not a risk. You don't need to test or worry. No risk.