i have a problem

we're set to go to the state fair three weeks from now and i just looked at my schedule and i have a doctor's appointment the same day.. i just called the supervisor of the living/housing site and told her but she said that she would call me back because she has someone in her office right now. i wanted to go to the state fair because it'd mean getting out. hopefully i can change the doctor's appointment because it's three weeks away but i have a feeling that my case manager will have something to say about it.