I agree with prism. Your loss is in the pressing process if your squares started exact at 2" AND if your seam is exact at 1/4". Each finished square in the center section should measure to be 1.5" square and the ones on the edge should be 1.75" Looks like you didn't push the top square back far enough when you pressed the pieces.
Other than that, the pattern is correct. 2+2+2+2 = 8 and you lose 1.5" for the seam allowance 8-1.5" = 6.5"