Ha, ha. Believe me, yes I have! recently I posted a pic of a quilt with hexagons with coffee prints. sigh. wanted to put a square in the corners of borders. That did not work out! I put it at the top of the border strip that was only cut the length of the quilt, not figuring in top and bottom border at all. sigh. So i finally did a half square in corner and left the square right under those. Looks like on purpose (hopefully). well it was really. I wasn't going to re-do that mistake. just wanted it done.
You can fix that, just think on it a bit.