I would say it's a good thing you are finally seeing GI doc. Yes, it sounds like you are having heartburn and maybe some motility issues in your esophagus. Let's not get alarmed because there is always the chance that it's something else.
Do the Tums help your heartburn go away? Have you every tried Zantac or Prilosec OTC to see if the heartburn issues go away. These would be indicators that it is acid reflux that's going on. Sometimes, heart problems can mimic heartburn also. Your GI may do an EKG on you.
When a GI suspects that you have acid reflux, they usually don't do any tests in the beginning. They put you on PPI (Prilosec, Nexium, etc.) and see what happens. If it works, your doc will have you continue on them.
Remember that everyone responds differently to PPI's. One may not work for you and another one will. I tried Prilosec, prevacid, aciphex...all of them only stopping my acid reflux about 50% of the time. Then I tried Nexium, and it worked good along with lifestyle changes.
If the PPI's don't work, then of course, your GI may do some tests to find out more....EGD, barium swallow test are good indicators of what's happening in the upper GI. If your acid problem continues without relief, the Bravo PH test is the definitive test to determine acid reflux...how long and how much acid is coming up.
Remember that if the PPI's don't work very well, your GI is going to assume that it's not acid reflux. You need to be your own advocate and insist on trying a different kind to see if it helps or insist on some tests.
Another thing to mention is that Prilosec and Nexium can work wonders for some people and they don't even have to change their lifestyles. My brother takes one 20 mg prescription Prilosec a day and it stops his symptoms and he eats and drinks whatever he wants. I, on the other hand, took the Nexium twice a day, but had to change my eating habits, plus sleep with my bed elevated to prevent night heartburn, no coffee, colas or citrus, tomatoe products, etc. Always had to watch it.
Please let us know what you find out after the doctor visit. I hope I've given you a good jumping off start... Welcome to the board!!