Hi, Sherrie, and welcome to the fibro forum. I'm not a doctor but this doesn't sound like fibro to me. You have pain in all four quandrants of your body with fibro. I have Crohn's disease and that can cause problems with white blood counts and fevers so it could be your ulcerative colitis. Or you might possibly have Crohn's. I was diagnosed for 11 years with UC and then they discovered it was really Crohn's disease. They are so similar.
I did a little googling and your appendix and gall bladder are on the right side but the pancreas is more on the left side. My brother used to suffer from pancriatitis and had a lot of pain. I'm absolutely just guessing here but it might be worth asking about.
Perhaps a second opinion would be in order. Sometimes doctors can't see the forest for the trees. After all, they are only human. How many times have we looked for something and couldn't find it but someone else can and it was right in front of our faces all of the time!
Please to let us know what you find out because we really do care about you.
Sherrine