Elevated amylase but normal Ct Scan

I'm 31.  Had gallbladder out in 05.  Had a stone near common bile duct & resulted with mild pancreatitis at that time my amylase was 328.  No probles since then until 2 weeks ago I had pain in the epigastric area that radiated to the left side & back.  My GP doc thought it was stress...ulcer & possible kidney stone.  I was on cipro for kidney infection.  I had really bad pain one night that almost drove me to the ER but it last 30minutes then down to a tolerable ache.  She drew labs & ordered CT of Abd/Pelvis.  Amylase was 317 Lipase normal, WBC slightly elevated.  The pain has gotten better..she started me on Nexium which alleviated the epigastric pain.  CT scan came back with pancreas unremarkable as well as all the other organs were normal.  The pain is much better just a twinge from time to time however, I have majorly changed my diet hardly any fat less than 25g/day I never was a drinker,  did take ibuprofen a lot for headaches, backaches, menstrual cramps but thats it no other prescription meds.  I just had the amylase/lipase rechecked and to much of a suprise to me the amylase is even a little higher at 332.  I don't understand as the pain is much better.  I am having surgery next Tuesday for a partial thyroidectomy & the pancreas stuff scares me.  The doc says not to worry about it & go ahead with the surgery.  The doc who took out my gallbladder said if I the pain is better to stop checking my amylase levels for a while.  HELP!!!  I'm not sure what to do.