How do i know if im suffering from hallucinations?

I have been having weird vision things like when I breath it looks like the walls are moving in a breathing pattern too. or things around me a subtly moving. Sometimes throughout the day I swear I hear people talking or things like a fan blowing even though I don't have one. None of these things are scary except answering questions for people and I have no clue how I know anything about the subject but the answer is always almost verbatim from some book I don't remember reading. Everyone things im some freak brain-guy and it has been going on for years. It wasn't until the last year or so the vision and hearing thing started happening though. Any ideas. P.S. sometimes I wake in the morning with books open or weird things pulled up on my computer but I never remember taking them out or looking up those pages.