Pain in right abdomen and back when lying down

Has anyone felt this? It hurts when I lie down it hurts on my back and right abdomen all on right side. It seems to get better or go away if I'm sitting up or laying on my belly which I can't do bc of my belly. I've googled it and found nothing. My doctor checked my kidneys with an ultrasound and they seem fine. It's just been going on for two weeks and j can't figure out what it is. Going to the bathroom (#2) seems to relieve it but only if I can go a decent amount but then later in the day if just comes back