What Causes Persentent Pain In The Upper Right Quadrant?

I am a 56 year old woman who has experienced pain in my URQ for almost two years now. I have had an MRI, CT Scan and recently seen a Gasteroenterlgist all which show nothing wrong. In addition I've had numerous blood tests with the same results. This pain has worsened and wakes me up several times during the night. I was completely healthy up until this pain started two years ago out of the blue. I eat healthy always have, exercise, am 5'6" and weigh 130 lbs. I'm frustrated and need to know what my next step should be. I feel this is something serious but medical profession cannot find the source. No unusual medical history, excepting fibroid tumors removed from my uterus last year after pain had already began.