Setback - followup

Just got home from hospital and good news, but kind of confused too.
I was given a thorough exam both lying down and standing up and the surgeon
could feel no hernia or tear. I asked him if an xray of some kind would show it, but he said since I only feel the pain when upright or moving, while laying down for scan probably would not show anything and his diagnosis is a sprained
muscle, but said to keep an eye on it and if it gets worse or changes to come in again.
So glad no surgery needed right now anyway, but pain is still there...strange.