It really just means that there is no excess co2 that needs to be released right now, or it is venting elsewhere...it doesn't mean fermentation has stopped or anything like that.
That's why you need to take a gravity reading, NOT go by airlocks. The most important tool you can use is a hydrometer. It;'s the only way you will truly know when your beer is ready...airlock bubbles and other things are faulty. So is looking at the amount of kra usen you have or whether it is still there or not . It could have been a very fast and clean ferment and the krausen could have formed and fallen quicky, or it still hasn't formed yet, since sometimes there's a 72 hour lag time before it even begins to form.
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....
Thinking about "doing anything" without taking a hydrometer reading is tantamount to the doctor deciding to cut you open without running any diagnostic tests....Taking one look at you and saying, "Yeah I'm going in." You would really want the doctor to use all means to properly diagnose what's going on?
In your case, wait till it's been 10 days and take a reading.