Thanks for writing.
You are correct that receiving oral sex (without or without protection) is not a risk factor for HIV. If the protected oral sex was your only risk for HIV we would not recommend testing based on that risk.
HIV is passed when blood and/or sexual fluids enter into a person’s body (ie. inside the vagina, anus, or penis). For HIV to be passed to someone while receiving oral sex, there would have to be significant blood in their partner’s saliva. Small amounts of blood will be diluted by the saliva in the mouth, and there is not enough virus to actually pass HIV. We do not see HIV being passed through receiving oral sex.
Regarding your HIV testing: The 4th generation HVI test is considered to be 95% accurate at 6 weeks, and 99%+ accurate after 12 weeks. There is no difference in accuracy if someone tests at 12 weeks (84 days), 90 days or 3 months. The reason some places say 90 days or 3 months is for convenience, people may remember this easier that 84 days or even 12 weeks. Your test at 67 days would be considered very accurate, and your test at 88 days will be conclusive.
Hope this helps. Please feel free to post a comment below or submit another question.