It looks a little torqued to me, as in not entirely straight -- the fabric has become somewhat angled or twisted. That may have happened with your first line of quilting if the sandwich was not tight, and then got worse as you quilted more lines. It will probably look fine when washed. Unless it looks worse than the photos show, I wouldn't take it all out.
I got a back on crooked and didn't realize until it was fully quilted. I didn't take it out, just chalked it up to experience. Now I check the back carefully before I begin and stop periodically and check it again.
Last edited by Friday1961; 11-06-2015 at 08:52 AM.