Losing weight but not moving sizes

I had my lapband surgery on 3/31 and I have lost a total of 31lbs, but I have not changed sizes yet. I figured by now that I would be able to buy smaller sizes, but I have,kt even had anyone say anything about my weight loss except my mom and husband. No one else knows that I had the surgery, but I would have thought that after 31lbs there would be some difference. I'm getting a little discouraged!