Problems!!!

Finishing my last row to sew into the quilt and "Z" is 1/4 inch short!  How'd that happen?   I've "unsewn " more seams in this quilt than any other.  This type of piecing seems like it would be easy, but not really, at least for me.  Also, as you see, I've decided on a flanged border to offset the squares. I knew I wanted a red border around the squares, but without the flange, the border was blending with the letters. A simple flange, although tedious, produced the picture I had in my head.  Happy Weekend!