It really doesn't matter. That's NOT the best gauge of knowing what your beer is doing.
airlock bubbling, lack of airlock bubbling, stopped airlock bubbling, fast airlock bubbling, slow airlcok bubbling, heavy metal airlcok bubbling, or disco airlock bubbling really is not an indicator of what is happening to your beer, really isn't important, and it is NOT an accurate gauge of fermentation.
If your airlock was bubbling and stopped---It doesn't mean fermentation has stopped.
If you airlock isn't bubbling, it doesn't mean your fermentation hasn't started....
If your airlock starts bubbling, it really doesn't matter.
If your airlock NEVER bubbles, it doesn't mean anything is wrong or right.
Your airlock is not a fermentation gauge, it is a VALVE to release excess co2.
Your airlock will more than likely slow down anytime now, but that doesn't mean that fermentation is done.
Fermentation is not always "dynamic," just because you don't SEE anything happening, doesn't mean that anything's wrong, and also doesn't mean that the yeast are still not working dilligantly away, doing what they've been doing for over 4,000 years....
The only way to truly know what is going on in your fermenter is with your hydrometer.
Like I said here in my blog, which I encourage you to read, Think evaluation before action
you sure as HELL wouldn't want a doctor to start cutting on you unless he used the proper diagnostic instuments like x-rays first, right? You wouldn't want him to just take a look in your eyes briefly and say "I'm cutting into your chest first thing in the morning." You would want them to use the right diagnostic tools
before the slice and dice, right? You'd cry malpractice, I would hope, if they didn't say they were sending you for an MRI and other things before going in.....
So after it's been about 10 days take a hydrometer reading and see whare the beer's at. And just becasue the yeast if finished fermenting doesn't mean it's job is done, the yeast, if given time likes to clean up after itself, getting rid of all the byproducts of fermentation that leads to off flavors.
That's why you wil find many of us leave our beers in primary for a month.
Even John Palmer in How to brew says;
Leaving an ale beer in the primary fermentor for a total of 2-3 weeks (instead of just the one week most canned kits recommend), will provide time for the conditioning reactions and improve the beer. This extra time will also let more sediment settle out before bottling, resulting in a clearer beer and easier pouring. And, three weeks in the primary fermentor is usually not enough time for off-flavors to occur.
I tell new brewers to forget what their airlock does or doesn't do, it's really a flawed tool, and not a "gauge of fermentation."