Ulcer or gallbladder?

I recently went to the er with abdominal pain. The pain was not specific to the right side, more of a bloated over all pain. They did a ultrasound and saw gallstones (not blocking anything), so the er referred me to get my gallbladder out, but also said it may be ulcers. The symptoms of the two seem very close.

For me it's bloated pain, gas, belching, a little back pain left side, heartburn.

Unfortunately, the soonest gi appointment I can get is 4 weeks away. I would hate to take out my gallbladder without need if it's ulcers. I did take a lot of ibuprofen before I realized how bad it is!

Looking for advice or others experience!