Actually, if the Center is being run according to AHA guidelines, the Instructor should ask to see your card before you're accepted into the class. I'm an AHA instructor and that's what we do at our hospital. Even if the card is one day expired, you have to go through the whole class. And that's not a bad thing right now because many BLS guidelines changed in 2006. The numbers are different and so is the use of the AED. It wouldn't hurt to go through the full day class to get all the new information.
Bite the bullet, get online, and see where the nearest class is being offered. Many times if you tell the potential employer that you're enrolled in an upcoming class, they'll still hire you with the understanding that you'll become certified within so many days. Good luck!