The only risks for HIV in adults are:
1) Having unprotected (no condom) penetrative anal or vaginal sex, OR
2) Sharing IV drug equipment with other IV drug users.
As you can see, receiving oral sex is not on this list. No one has EVER been infected with HIV from receiving oral sex, and you will not be the first.
Also, hygiene is not indicative of whether someone has a disease or not.