Eggs that have reached their expiration date typically remain good for another 3 or 4 weeks. FDA regulations require newly cartoned eggs to carry an expiration date 30 days from the time they were packaged.
A quick way to check if an egg is still good is to place it in a glass of water. Bad eggs float to the top due to gases that have accumulated in the shell. Good eggs drop to the bottom.
Another way to tell if an egg has gone bad is by the smell. Crack the egg open, and if the smell is unpleasant, chances are good that the egg is bad.