Remember airlock bubbling is not a true sign of fermentation, only your hydrometer is....
The airlock is outgassing oxygen initially and more importantly co2 (which is of course a byproduct of fermentation), but there are a lot of variables that come into play in terms of the airlock bubbling...You could have for example and bad seal between the grommet (or stopper) and the airlock, or the lid on the bucket isn't fully tight and gas is getting out elsewhere besides the airlock, or the stopper and mouth of the carboy and that would appear slow, while fermentaion is actually occuring rapidly... Or the little bubbler in the airlock could be sitting a little crooked, or become weighted down with tiny co2 bubbles and need to build up a good head of gas before blurping again.
Even having the airlock leaning slightly askew affects it.
I've got a beer in my fermentor that has had almost no airlock activity, but I see the liguid in the airlock is saturated with tiny bubbles so I'm pretty sure activity is occuring...But I won't really know until I take a hydro reading...But since I used a smack pack of yeast and a big starter I trust that the yeasties are doing their jobs...But my last beer on the other hand, the brown ale I pitched on a yeastcake from a previous batch sounded like a machine gun the way the bubbler was going up and down...I ended up needing a blow off tube once it got going...
So as you can see airlock activity varies, and should not be used a a sign of speed or lack of fermentation.
Either way, your beer is fine...It takes a lot to ruin beer....