AG,
The first thing I think you should do is to rule out any nutritional deficiencies with your doctor. Imbalances in electrolytes, and Potassium specifically can be a cause of leg cramps.
Look into this possibility first, and then go from there as far as looking for causes.
For now, making sure you are hydrated, stretching frequently and massage should help bring you some immediate relief.
Hope you find your answers soon.
S.C.