post heart stent pains

I've had chest and back pains,more like twinges and pressure, since 3 stents put in LAD in Aug 2009. Occurs almost every day. I had to us nitro on two occasions which seemed to help. I can walk at a brisk pace without any symptoms but notice it when at rest. I went back to cardiologist about three weeks after stent and he did a stress echo which was normal.My wife keeps telling me to go back to Cardiologist....has anyone else out there been told this is normal?