Anything's possible with an airlock. I've had them bubbling away on weizen brews in 10 hours, other brews might take up to 2 days. And I've had more than a few brews never bubble an airlock even once. Same end result on every one of those though.....great beer.
Airlock is a convenience more than a tool for measuring fermentation. Watch your brew for a krausen, and if you're concerned that it's not fermenting (which would be very unlikely btw), take a gravity reading. If it's lower than your original gravity reading, the yeast is doing its job!