Have you already trimmed off your batting and backing?
I used to trim all 3 layers of my quilt to be the same before adding my binding. It was so frustrating to finish and flip over the quilt to find all those places where the backing or batting (or both) had shifted or folded over. I got tired of using a seam ripper to fix all this stuff. Then, I started to leave all 3 layers of my quilt un-trimmed until AFTER adding the binding. I like to be able to see all 3 layers of my quilt as I add the binding. No more ripping out seams on my binding.