I quilt on my regular sewing machine. When I am quilting the first two thirds of the quilt is almost flawless and the last part has lumps. It is where I quilt one way then go the other way and where my seams meet one side is bigger than the other and it c

From your description it sounds like a basting issue. With machine quilting the rule of thumb is to pin baste starting in the center of your quilt and move outward about every four inches or a hand width apart. Most of the time shifting happens when the quilt has not been adequately basted.