trivial scratches, cuts, etc do not pose a measurable risk.
you had NO risk and do not need testing.
if the prostitute is is carry hiv but i wearing a condom inserting, due to inserting condom just cover half of penis when rubbing.does any possibility infection due to finger scratch to penis injury? if the injury is exposure, should i go for blood test?
but if wearing condom, penis injury due to finger nail scratch explosure, that also didn't have risk?