You did not need to test for HIV. Giving oral sex ( or receiving) is never a risk for HIV. Air and saliva inactivate the virus. The only risks to acquire HIV are to have unprotected vaginal or anal, penetrating intercourse or share IV drug needles. So, you had zero HI risk. Regarding other std's, there is minimal risk. In the absence of any symptoms, I would not be concerned.
Move on man, your risk was so small to start with. Oral sex is not a good way to transmit STIs. In lieu of symptoms and with the risk we have told you testing is not recommended.