As someone who has experience in making mistakes...I would suggest going through each block, and measuring it. You can try it on top of the quilt, and see if every thing is equal. If they seem to be equal, turn over your quilt and look at the seams, are they all 1/4 inch? If you find by measuring each of the 'larger blocks' that some are off, reverse stitch and fix. I would guess it may be your 1/4" seams. That's what it would be for me!