You may have calf pain beucase you have over-exercised that muscle. If you have recently worked out, or worked out that specific muscle area, rest for a day, stretch the muscles daily and exercise it 3-5 times a week.
Calf muscle pain can sometimes be caused from not drinking enough water everyday. Also if you are tking cholesterol lowering medication it could be a side effect of the medication and you would need to see your doctor becuase this side effect can be serious if not taken care of.
You're probably experiencing a charlie horse, which is a very bad cramp. A lack of potassium and/or calcium can cause this, and a daily vitamin can help.
Calf muscle pain can be cramping due to vitamin deficiency - calcium or potassium or very commn It could also be gastroc shortening due to wearing heels.