If the quilt was not evenly stitched over the whole quilt, the outside edges may be wavy. You may need to add more stitching near the outer edges. Since your quilt is done, there is no going back and using the excellent suggestions for "in the future" although blocking your quilt could help.
This happened to me only once and I hope I have learned my lesson.
I had already put on the binding. I removed the binding. By hand I took needle and thread and did a slight gathering along the binding edge by stitching for three inches...pulling slightly to gather and then an overhand stitch 2-3 times to "lock" the gathering...stitch three more inches...repeat. I was able to cut six inches off the binding when I rebound the quilt. Maybe this could work for you. Good luck!