Re-print?

Many markets ask for only a year or so of exclusive publishing, although it's not really wise to assume. If it was an email contract, you can search your inbox for it (if you store emails) or your 'sent' mail folder if you scanned & emailed your signed version. Barring that, see if any of your fellow authors in the anthology have since reprinted their stories. But I don't suppose I need to tell you that from now on, always keep track of your contracts (or at least the expiration dates!)

Don't rely on your memory alone. You have vague recollections about what that passage said, and you could get burned if you aren't correct. Track down your copy of the document or contact the publisher for another so you are Absolutely Certain.

Seconding what Ben said.

You signed a legally-binding contract. You can't just hope now that you get things right: you have to adhere to that contract. If you can't get hold of a copy of it to ensure you're doing things right, you shouldn't do anything with that story.