This is a common design layout. It depends on if you have an even or odd number of repeats of your border block on that side of the quilt. Just remove the HST block in the corner and replace it with a plain square. The opposite corners should match each other, with two being blunted and the other 2 squared off. As you look at quilt pictures you will find other quilts with this pattern. This is one of the reasons why sketching out your quilt is a good idea.