Your situation involves personal contact with an object in air (her skin, lips, mouth, saliva etc. which is not a risk for hiv.) No 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. THis is the same thing Guitar said so move on and stop focusing on accuracy of your placebo test, since it will always be negative for people who had no risk.
Oral unprotected sex is NOT a risk for HIV. You never had a risk. The only risks for HIV include having unprotected vaginal or anal sex or sharing IV drug needles. Air and saliva inactivate the virus. No risk. For general informational purposes, 4th generation tests are conclusive at 28 days. But you didn't even need to test.
Exactly what kind of low risk exposure?