The purpose the airlock is to keep contaminated air from getting to your wort while letting CO2 out, not as a guide or indicator of fermentation. That's the hydrometer's job.
Make sure your lid is on all the way, sounds like you have fermentation going and nothing to worry about.
Kegged: Berlinerweisse, Dubbel, Galaxy Wheat
Bottled: Golden Strong, Mild, IIPA, Rauch
Fermenting: Saison, Imperial Wheat Stout, Brett Saison, APA, Brett Roggenbier