Question: Sharp, stabbing chest pains on the right side

For approximately three months, I have been having sharp, stabbing chest pains on the right side. They occur behind my breast, towards my back and only when lying down. Sometimes I have a tightness when not lying down. I have kept a food journal and have not identified any correlations. I have had a chest x ray and and ultrasound and both showed nothing. I have had bloodwork done for celiac, my pancrease and just general work ups and all my levels are find. I have an endoscopy next week. A round of prilosec did not help nor do anti-inflammatories. My PCP does not appear super concerned and is not best at outreaching me when results come in. I did see a GI specialist, who thinks this is not GI related. What other directions should I go in