If all your tests come back negative, then you may wonder why you are having pain in your upper right quadrant (URQ), and what it most likely is is referred pain from tight back muscles, most likely caused by your unconscious tensing of your back muscles in the "flight or fight" reflex. It is a very common manifestation of anxiety, but often leads to a greater panic than some of the others because of the many organs located on the right side of the body, like the gallbladder and liver.
If you have anxiety illness try to get to the bottom of it; otherwise this pain may come back or get worse, and then you end up afraid of the symptoms and in really bad shape psychologically. There are many sources to help with anxiety. This site is one.