Hi Jon,
Pain in the calfs I have experienced.
First a number of questions,
Are you a new runner?
Have you got the right shoes?
Do you stretch before/after running?
What time of day do you go running?
How hard are you running?
Is the pain in the lower or upper calf?
How often do you run?
Do you do any other excercise?
Hopefully you're a new runner in the wrong or old trainers who doesn't stretch much.
In which case, total rest for 4 days, 7 days of walking for 30 mins followed by some calf stretches & get some new trainers from a specialist running shop. After 10 days you should be able to run again, starting slowly & building in peed & distance slowly.
You could allways visit your GP who will konw a lot more about it than me.
Best of luck
PM