Thanks for posting your query.
With an undetectable viral load
the chances of getting HIV
is remote. Herpes would likely to spread easily. 2 painful lesions started to crust , where? Is it in your groin. Genital Herpes
will appear as grouped vesicles and subsequently leads to grouped tiny ulcers may or may not be painful. It will heal spontaneously after a week or two.
HIV prophylaxis has to be taken has to be taken within 72 hours of contact. After that it will not be useful.
Anyway you have to consult a physician and to follow his advice in this regard.
Get well soon.