LOL. I've done the same thing: I couldn't resist a super cute dress that didn't fit. The only difference is that I still can't fit into mine! Way to go girl! I recently read that that's one of the best ways to gage your weight/fat loss: use clothing that's too small or too tight rather than getting discouraged by a scale that keeps going down, then back up again.
Keep up the good work. You will look awesome where ever you decide to wear your new dress!