Everytime when I am awake for 4 days I get no hallucinations

I once got to 4 days (with amphetamine) and all I experienced was that the world started to feel off and colors were vibrant. I never got to experience any horrifying or just realistic hallucinations, at worst fague shadows or a spider in the corner of my eye. I know it differs for a lot of people and I was wondering how many days or what it takes for you guys to start seeing things.