I Am A Runner And My Left Calf Became Very

I am a runner and my left calf became very tight and painful after a run 2 weeks ago. Since that time I have not been able to run. I have tried to run 3 times but the pain and stiffness keeps coming back. I have 2 questions. (1) How much more time off (no running at all) should I take? (2) Is there some kind of cross training I could do like stairmaster machine or bike? Taking Ibuprofen seems to help but I hate to take a drug like this for a very long time. Please advise