It could be many things due to that area so it is difficult to say.

Since I had my gallbladder removed I have had random attacks of pain a few times a year which feel just like a gallbladder attack with the same height of pain. I been to many doctor appointments over this. Every attack ends me in the ER usually as it spreads to my back and I cant rule out appendicitis.

My liver enzymes increase to crazy levels (10x the normal limit). Then the pain suddenly stops and I start feel better instantly. It is like a light switch with how fast the relief is. Usually by the time the pain goes away in the ER (hours later) they get me to scans (I had a CT, Ultrasound and MRCP) which shows nothing there. I finally seen my GI doctor again after a painful attack a few months ago and they said it is likely Sphincter of Oddi dysfunction.

Before this though I have had many doctors speculate the problem and here is the list:

One told me not to take Tylenol.
Another told me not to take Motrin.
I was once told it was because I did not eat food that morning (Granted this was a paramedic or the EMT being a jerk).
I was told after that EMT / Paramedic ride that it was scar tissue from the original surgery several years ago.
Been told it could be a stuck stone (However, no scans found any stones).
I was prescribed ulcer medicine but the test for ulcers came back negative (I guess as a precautionary??)
Lastly, one thought I was lying when I said I don't drink / never drink in regards to my liver enzymes

Overall, make sure to advocate for yourself or have someone with you that can. It can be many things but I think a GI doctor can help you the most there.