What's your current status? If it's H1-b, you should have I-94 on your H1-b approval notice. Maybe that will work, as well. I remember the officer took that I-94 off my H1-b approval notice when I got my passport stamped. Don't worry too much. Just explain your situation to your attorney if you have one or explain to the immigration officer if you don't. Definitely, this is a lesson you ought to learn.