I have been there. Actually on two quilts. One was Thimbleberies quilt where I put the flowers block on upside down and it was a long time after the quilt was done that someone brought it to my attention. The other one was a sampler which had been quilted and binding on before I realized I had made a mistake. Both had been quilted by a long Armer so I was not about to start taking them apart. But since both errors are close to the edge and it is not binded yet. I would try and fix it.
But it is a very nice quilt.