Suggest Treatment For Cramps And Burning Sensation In Calf Muscles

i have been in a hard cast for 2 weeks and in past 3-4 days started experiencing pretty painful calf cramps with a burning sensation. They r worst when i get up after sitting 4 awhile. It is my ankle that is broken but right now my calf muscles that r killing me. I have no insurance so am trying to only go to Dr. for the absolute necessities. Was planning to wait about one more week to get it off and re-xrayed (about the half-way mark), although they wanted me back yesterday. Is this normal? Cast doesnt really feel too tight- in fact there seems to be a little bit of movement since first few days swelling probly went down. Any advice besides go back to Dr.?