For HIV, the only risks in adults are:
1) Having unprotected anal or vaginal sex, or
2) sharing intravenous needles with IV drug users.
You cannot get HIV or any STDs from a hand - not your hand, and not anyone else's hand - no matter what is on the hand.
If you were "a bit tipsy", and not black out drunk, you'd know if she gave you oral sex, even with your eyes closed.
Also, assuming she's a sex worker, she'd have charged you more.
In any case, receiving oral sex is considered low risk. Most experts don't feel that one encounter of unprotected oral sex warrants testing, but if you are concerned, just test. The only risks here are for syphilis, which is uncommon in most developed countries, genital herpes type 1 (if you don't already have it orally), gonorrhea and chlamydia.
I doubt you got oral sex and didn't know it. If you were in total darkness with a stranger, and your penis was out - don't do that again. That's never a good idea.