Lingo CGM margin of error?

Hey all,

I wore a CGM over the summer and am wearing another one now. My average glucose is showing 99 (which would make my A1C a 5.1), but my most recent blood test showed an A1C of 5.8.

Is this just giving my a better idea of what my next blood test might show, or is it possible this is within the CGM margin of error?