On Midwest's website it says carry-on cases should be 21x14x9-1/2. My case says on the tag that it's 20x14x9, that's how much the actual case measures. When you add on the wheels it's almost 22", will it be too big? The wheels don't retract or anything. I can still take it back I think, I bought it about 3 weeks ago. All of sudden I decided to check the size. What do you think? Thanks!