intermittent right sided abdominal pain

I am a registered nurse who has been experiencing intermittent sharp stabbing pain just below my rib cage right side through to my back for almost 12 weeks. No injury or strain brought this on it is worse at night and in the morning it is preventing me from sleeping and wakes me. If I get into a comfortable position I am ok for a bit but movement and sneezing can make it unbearable. If you press between just below my sternum it is very painful and radiates through to my back on my right side. I have had chest xray which showed a probable hiatus hernia (my doctor does not think this is the cause or significant since I have no reflux or trouble eating). I have had abdominal ultrasound and chest and abdominal CT and all have come back negative. Blood work was all negative including a D-dimer negative urine negative but I am still in pain. The pain gets less sometimes and sometimes eases after eating but rarely goes away completely. I have tried rest, nsaids, including advil, arthrotec, mobicox, and also pariet and buscopam. I also tried a combination of tylenol #3 and nsaid's, nothing seems to work and I am lost for answers. It has been suggested to me a possible peptic ulcer by someone else online.
The only thing I can think is could it be a disc issue causing radiating nerve pain? I do not have any back pain. Also a couple times when it was so bad I seemed to be having right shoulder pain as well. ?diapharmatic pain.
I am eating and drinking ok, going to the bathroom fine and otherwise am in good health I am not obese and have only mild asthma I am 37 and was active previous to this. Any ideas would be helpful. Also no part of my rib cage is painful with palpation, squeezing my ribs in any direction does not make the pain worse the pain radiates on my right side under my ribcage and I am very tender to palpate just below the ribcage from just below my sternum to my right side any pressing here I feel as pain and it radiates through to my back. I have tested my stool for occult blood this morning and it is also negative. I have started pariet as a precaution yesterday just incase it is a peptic ulcer but it has not yet had an effect.