Recently, I have sex with an unknown status sex worker, she gave me oral sex, after a while, she spit some phlegm on my penis and continue giving me oral sex, I'm worrying about will phlegm transmit hiv through oral sex? I'm very afraid
HIV is inactivated in saliva and air which means it can't infect from oral. So those are 2 reasons you had zero risk. Double zero risk.
No one in 40 years of history got HIV from oral. Even with blood, lactation cuts, rashes, burns etc saliva and air do not allow inactivated virus to infect, so you had zero risk