Actually your airlock is more like your baby's (and your) anus, then it's heartbeat.
Your airlock is not a fermentation gauge, it is a VALVE to release excess co2. And the peak of fermentation has already wound down, so there's simply no need to vent off any excess co2.
Your "baby" is either farting excess gas, like we do, or it is not...nothing more.
The bubbling just means that it is venting excess CO2, nothing more. If it's not bubbling, that only means that it is not producing enough co2 to need to vent.
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.
Fermentation is not always "dynamic," just because you don't SEE anything happening, doesn't mean that any-thing's wrong,, and also doesn't mean that the yeast are still not working diligently away, doing what they've been doing for over 4,000 years.
You'll be much happier if you get out of that habit, of equating airlock bubbling with fermentation...you will find that fermentations rarely don't take off, or just Stop...In fact I've never had a beer not ferment. BUT half of my fermentations, spread out across 9 different fermenters, never blip once in the airlock.
What is happening is that fermentation is slowing down, and therefore not producing excess co2, and therefore not NEEDING to bubble.
Just leave it alone for at least another 8 days OR MORE, they you can take a hydrometer reading and decide if you want to secondary it...OR you can do what many many many of us do and leave your beer alone for a month, that will let the beer finish fermenting and then let the yeast clean up after themselves, that way they will get rid of all the byproducts of fermentation that often lead to off flavors, and if new/impatient brewers move to soon, they end up stuck with.
Thoughts about that have shifted over the last few years, now we have found that leaving the beer in primary for a month improves the flavor of beer by cleaning up the byproducts of fermentation...There is about 1,000,000 threads about it, including at least 5 threads active today alone in the beginners section...look for threads about secondary, long primary, no secondary, long primary, autolysis, and you will see our answers, over and over and over again.
All my beers stay in primary for a month, been doing it for 3 years now, and have won awards for my beers doing so....
Even John Palmer talks about this in How To Bew;
How To Brew said:
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.
But in other words, everything fine.
