Pain that comes on with exertion and eases with rest is suggestive of a cardiac problem.
Seeing a doc is obviously the first place to start. When you made the apt., did you tell the desk that you were having chest pain with exertion? Also, your age, smoking history, family history and any other medical problems or medications you are taking could all tell part of the story. Depending on your community, it sometimes takes weeks to get an apt. I, personally, wouldn't wait that long.
If it were me, I would call back and ask when the soonest you could have treadmill scheduled. I hate to be neurotic (it is in my nature) but there is so very much one can do to preserve heart muscle before a heart attack.
And, if you are like me, you will worry until you have a clean bill of health.
Aren't I just a little ray of sunshine

Sorry.