Have you tried following a low fat diet - and I mean really low fat with no cheating - to see if it makes a difference? The tests aren't perfect for gallbladder issues, unfortunately.
and wearing an underwire bra, as screwy as it sounds, try wearing one without the underwire and see if it makes a difference especially if you're developing a 'concavity' under the breasts that some women get. That change in bone structure and the pressure can press on nerves of the celiac plexus and cause some organ pain.