I agree that what you describe is not a risk for HIV and the risks are stated above. No worry, no risk, no need to test.
It is not possible for you to get HIV through your finger, or any other body part. The only sexual risk for HIV is when an unprotected penis is inside a vagina or anus. No other sex event that you can think of would put you at risk for HIV.
Do not have unprotected intercourse with someone of unknown status, and do not share intravenous needles with other people, and you will never have to worry about HIV.
Your situation involves personal contact with an object in air ( vagina, fluids including possibly blood, sores, etc.). No hiv worries, because you can't get hiv from personal contact except unprotected penetrating vaginal or anal, neither of which you did and you didn't share hollow needles to inject with which is the only other way to acquire hiv. Analysis of large numbers of infected people over the 40 years of hiv history has proven that people don't get hiv in the way you are worried is a risk.
HIV is a fragile virus in air or saliva and is effectively instantly dead in either air or saliva so the worst that could happen is dead virus rubbed you, and obviously anything which is dead cannot live again so you are good. Blood and cuts would not be relevant in your situation since the hiv has become effectively dead, so you don't have to worry about them to be sure that you are safe.
There is no reason for a person to test when they are safe. The advice took into consideration that the other person might be positive, so move on and enjoy life instead of thinking about this non-event. hiv prevention is straightforward since there are only 3 ways you can become infected, so next time you wonder if you had a risk, ask yourself this question. Did I do any of the 3? Then after you say "No, I didn't" then it's time to move on back to your happy life.