I am making my first fence rail quilt. I cut my strips 2 1/2 inches,sewed them at 1/4 inch and when you lay them side by side you can see they are the same size which is 8x8 but when you turn the second block to start making the fence rail the size doesn't match. What am I doing wrong? When I watch tutorials on this the I do according to the instructions. Please help. Thanks