bicep pain

I am experiencing mild pain in my left bicep during my arm workout.
It occurs on the contraction phase on the outer muscle area, at its insertion pt. near the elbow at the top of the radius.
HELP what do I do to reduce the pain and thus get a better excerscise. As I was taught if it hurts stop and reduce, but when do I heal and resume a more rigid training?????? what could I have doneSigned frustrated,thank you mike