Depends. How long have you been awake? How often are you sleep deprived? I found that when intensely sleep deprived I started to "hear" things long before I started to "see" them, and usually "seeing" was really "misconstruing actual shapes to be other than what they were." Like, shrubs for people, etc. I assume this is a result of midterms or something?
Took three 45-minute naps since 6:30am yesterday morning. That's not that bad as far as I'm concerned, but I usually miss a night of sleep at least weekly. I sleep ~5 hrs a night plus an hour in the afternoon. My sleep schedule is fucked. Intense school classes and piano, SATs, college apps on top of it... I'm not stressed, just overwhelmed.
If you are already prone to hallucinations you might snag a few, if not though I would not worry much about it. Sounds like you have enough on your plate. You will probably just feel loopy and out of it. But yes, your sleep schedule does sound awful. From what I understand, hallucinations can occur around 3 days of sleeplessness or so.