Chest pain with neck pain, any chance it is plavix related or related to neck tension?

I am a 53 yr old female who had a non-coated stent implanted 07-28-08. Had a 2nd cath 08-06-08 after ER visit with chest pain and all was clear. About a week ago began having off/on chest pain with lots of neck tension. Neck makes crackling noise when I move from side to side.  Have been exercising and watching diet.  Wake up feeling fine and the neck somewhat rested but twinges of chest pain develop throughout the day and the neck feels tense.  Some days there is nothing.  Exercise (rowing/walking) has not produced any chest pain.  I'm wondering if this could be caused by taking plavix?  I take the drug early in the AM and am usually feeling less chest pain symptoms at night.  The neck generally always feels tight but better if I do some neck exercises.