I always think of that too, for upper right abdomen. My gall bladder was removed in July 2016. Had what I later realized was a gall bladder attack the previous January - only very slight nausea but considerable pain over a weekend where I thought that if it got any worse, was definitely going to have to go to the emergency room. Took a lot of Ibuprofen and waited it out, and it subsided.
Then came July and one evening it was back, even stronger pain that time. By then I was really figuring “gall bladder” and that if it didn’t clear up fast, the hospital it was. Next morning headed to the hospital, and had blood and urine tests, an ultrasound, etc., and fairly soon the doctors said, “Yeah - gall bladder needs to be removed.” Afterward, the surgeon said it was “very inflamed and full of stones.”
It was not just tightness/discomfort that I felt - it was serious localized pain, like a medium-small ball in there, quite alive with pain. It hurt more to breathe in, I presume from the expanding lungs putting pressure on the gall bladder.
Gall bladder trouble will feel differently for different people. The pain can vary, and nausea or even vomiting are common.