I would fully expect myself to have convinced myself that I am not experiencing hallucinations - particularly because hallucinations are often incredibly minor.

I am also very mindful about the dangers of telling people things that will alter how they interact with you.

Combining these I find it likely that there be a very high bar for knowing something like that - especially as it is likely a personal suspicion. Not all doctors qualify as over this bar.

Of course I would actively seek a doctor I was comfortable disclosing everything to, yet I understand a reluctance to do so.