You can not seroconvert to positive since you did not have a risk. It doesn't matter whether you had a sore on your penis, saliva contains proteins that inhibits the virus.
Even if your partner was HIV positive, Oral sex is not a risk. Getting a blow job wouldn't give you HIV, it never has, not in the history of HIV transmission. PEP was not needed. Not sure who gave you PEP for oral sex, it is PEP not Antacid!
Seroconversion only happens to people who were exposed and then infected with HIV. You were neither exposed nor infected so it is totally irrelevant to your situation.