Is it possible that OA can not be seen on Regular X Ray?

I had X Ray done, showing some degeneration in finger joints, but "normal" reports on shoulder X Rays.

I have had flares of joint pain that travels from one joint to another over periods of days.
My shoulders are painful during certain movements in addition to aching flares.
Should I ask for MRI ? ( something is not "normal")

I do have a Dx of RA as well.

Thanks for reading