Your bubbles stopping only means that it's stopping bubbling, NOT necessarily that fermentation has halted. More than likely it's just slowing down, like all fermentation does.
You have fermentation. IGNORE what your airlock is or isn't doing. And trust those of us who've been doing it longer than you?
Bubbling doesn't really mean anything other than the airlock is bubbling. And airlock is not a fermentation gauge, it's a vent to bleed off EXCESS gas, be it oxygen or EXCESS co2. It shouldn't be looked at as anything else, because an airlock can bubble or stop bubbling for whatever reasons, including a change in temperature (gas expands and contracts depending on ambient temps) changes in barometric pressure (You can have bubbling or suckback in the airlock, depending on pressure on the fermenter) whether or not a truck is going by on the street, the vacuum cleaner is running, or your dog is trying to have sex with the fermenter. Or co2 can get out around the lid of the bucket or the bung...it doesn't matter how the co2 gets out, just that it is.
And bubbles don't coordinate with anything concrete within the fermenter either, "x bubbles/y minute" does NOT TRANSLATE to any numerical change in gravity....if an instruction says do something when bubbles do something per something, throw the instructions out.
Fermentation is not always dynamic, just because you can't see what's going on, doesn't mean nothing is going on. And just because your airlock starts up, and then slows down or stops in a few days, doesn't mean fermentation is over YET, it just means the excess co2 is not coming out of the airlock...not that the yeast is done.
The only way to know how your beer is doing is to take a hydrometer reading, if you're worried. But not until 72 hours have gone by. Then if you're still concerned, take one...then you'll know.
Counting bubbles does not equate to anything usable in fermentation. It's not like "x bubbles/minute= y gravity points." It just means that co2 is being released....but it could also NOT be bubbling, and still fermenting away.
Relax, leave your beer alone and let it do it's thing for a couple more weeks, and most importantly, IGNORE what your airlock does or doesn't do.
In fact you might find this discussion
on the superfluousness of airlocks something that will help you get a handle on this. It was started by a newer brewing who just grasped this concept.
The way to determine if fermentation is complete, is to take 2 grav readings over a three day period. Not by counting bubbles.