1972-D Lincoln Penny with missing reverse

Today I headed over to my bank, got my 2500 pennies, took them home, opened the first role, and 10 coins later I found a 1972 D penny with a completely smooth reverse. As if the planchet was never struck. Now the Lincoln side looks completely normal and it has a rim, while the other side has no rim of any kind. I don't have a scale so I cannot weigh it. I heard that if two coins got into the machine together they would mint one image on each coin leaving the middles blank. I have NEVER dealt with errors before, and I have no idea on the legitimacy of this find. Any help? I'd post pictures, but I have a horrible camera, and there isn't much to show.

Uhh well I dunno what to tell you, man.

It's an error, the way you describe it. It's something that wouldn't appear in ordinary change, that's what I can tell you.

If you are listing the coin, do not list it as a new year, but put in the Personal comment box that you have an error coin.

Okay, thanks. I'll take it to a shop and have them weigh it for me. I want to make sure the reverse just wasn't sanded off.