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, getting scratched by barbershop trimmers is not on this list. I don't know what is causing the rash on your palms, but that isn't an HIV symptom at all, and you could not possibly have HIV symptoms since you had no risk for HIV.
When should you test? NEVER. You didn't have a risk.