I agree, it is not a copperhead. It may be a water snake, or perhaps a fox snake.
A few people have suggested the posability of a dry bite, and suggested that young snake are mor venomous than adult snakes. These two assumptions go hand in hand, but both are false. A baby snake does not posses more potent venom then the adults, they simply lack the ability to control how much venom is injected. This means every bite from a baby snake will be a hot bite, were as not evry bite from an adult snake contains venom becuase they can control its use.
Somone else expresed the fear that you would be dead or paralized if you had been bitten by a copperhead. This also is not true. Copperheads posses hemotoxic venom, meaning it destroys blood cells and tissue but dose not cause paralasis. Also it is very rare to die from a copperhead. I do not recall the exact numbers right now, but it takes somthing like 100 mg. of venom to kill a healthy adult. However copperheads are only capable of injecting about 75 mg. of venom. Most deaths occur due to reactoins or from bite from multiple snakes.
One of the instructers were I got my degree (recreation and wildlife management) was biten by one of the copperheads he kept. He recieved the bite in a moment of stupidity (talking to a girl on the phone to schedule a date while trying to change the snakes water) He described the bite as being able to "ruin your weekend" (i.e. imense pain) but not somting that would kill you.
Lastly, the idea that copperheads must chew the venom into you was mentioned. This also is not true. They are not rear fanged, the are pit vipers and thus are front fanged. (pit vipers poses some of the most advanced fangs, the are retractable, not fixed)
I'm sorry for the long post, but I prefer to dispel reptile rumors whenever I can.