chest and left arm discomfort, mouth sores

I have been having chest discomfort for about the last two weeks and so far my doctor has been unable to make a definitive diagnosis.  The pain seems to come and go without warning.  I am mostly at varying levels of discomfort.  It feels like a burning pain usually in the center of my chest radiating through to my back and up into my throat.  Sometimes I get a sharp pain beneath my left breast and at the top of my rib cage.  The last few days my left arm has been achy, more so at night.  Sometimes the pain reaches all the way down to my hand and fingers.  I've also noticed a couple (canker?) sores in my mouth--I don't know if they are related since I occasionally get them if sick/stressed.

The orignal diagnosis was anxiety and I was given Alprazolam, which had little effect on the pain.  I had similar chest discomfort in December and had an EKG done, which came back normal.  I had another normal EKG a few days ago.  I have had blood work to check my blood count, metabolic panel, thyroid function, and glucose.  All of these came back normal.  I am a 24 year old seemingly healthy female.  Any ideas...?

[shasta_narnia]

did the dr. check you for reflux or gallbladder issues?  i too had very similar symptoms last fall - finally went to the dr. - and was diagnosed with gallbladder disease - just had it out last week!  have you tried changing your diet?  perhaps some foods are causing the problem?  i went on a low fat diet for a while and it made a big difference.  anxiety can also cause these issues - and sometimes the medication takes a while to work - but i would check into the reflux/gallbladder too!  as for your canker sores - i wouldn't be too worried about them - though i know they're painful - ususally they're a sign of stress, as you already mentioned - and it sounds as though you're feeling stressed!  remember - your ekg and blood work shows no problems with heart etc - so try to relax (easier said than done, right;-) and talk to your dr. about some of these other issues -or if he's already ruled them out, give your anxiety meds some time to work  - can take up to a month to see much change.  hope this helps!!