Mine is in the brew fridge right now and will go out to the shed tomorrow for conditioning. I didn't seem to get a lot of airlock activity, but then I used Dark Rock's enhancer, which comes with Pure Brew. In my experience, Pure Brew always makes for a less vigorous fermentation.
If you used Pure Brew, it could explain it. Failing that, your fermenting vessel could be leaking. This shouldn't affect the final beer, but if the gas is escaping from the vessel, it follows that the airlock will be less busy. You could always run some gaffer tape around the edges of the vessel to seal it. What temperature are you fermenting at? If it's too low, the yeast could have stopped doing its thing. If it's below around 18/19ºC, try wrapping a blanket around the vessel (unless you already have some temperature control in place).
Did you take an OG reading on Sunday?