Can i contract a decease from chewing on a used band aid that was in the food? no blood appeared to be on it.

Disease spread: It would be incredibly unlikely. Nothing is impossible, and there are many food borne illnesses, but a used band aid that was on a superficial skin wound, is likely to harbor only superficial skin organisms, which should be digested by saliva and gastric enzymes. If there was blood on it, and it was from someone with hepatitis C, and the blood was fresh and hadn't tried out, it is possible.