I was diagnosed with acid reflux and IBS two or three times before they found my bad gall bladder. Took them 5 years to figure it out, even though me and my mother both were telling them that's what was wrong with it. In fact, everyone in my family diagnosed me quicker than the doctors because everyone in my family has had a bad gall bladder! (Genetics, you think???)
If you want your gall bladder looked into, insist on a hida scan. That checks the actual function of your gall bladder, independent of stones (which I did not have). The first two I had were inconclusive and fine respectively. In hindsight, I realize now that the reason why my obviously bad gall bladder did not show up on them was because I was having an "okay" period. I had my third one when I was having a real bad spell. If your gall bladder (assuming this is even the problem) is like mine and it randomly malfunctions, it may be hard to catch with a test. I have recommended to people who suspect their gall bladder but who are having a good spell when their test is scheduled, to try and precipitate an attack the day before your hida scan. Things that almost always brought an attack on for me: caffeine, fried fast food, pizza. Some people also have a doozy of a time with spicy foods like Mexican and Indian.
I have also heard of the four F's that increase your chances of having gall bladder disease: fair, fat, female, 40+. I hit three of the four of those. Some people also add in pregnant as apparently having children makes it more likely to go bad. Also, my surgeon said that people of Native American descent are at risk because apparently it's quite prevalent among them (I also hit that marker).