Pretty soon someone will get in this thread going off about how a bubbling airlock doesn't mean crap. So it might as well be me. Just because the airlock isn't bubbling doesn't mean that the beer is done fermenting. The only way to tell if it is done fermenting is to take a gravity reading. If it's the same gravity 3 days in a row, then and only then do you know it's done. If you have yet to hit in the ballpark of your suggested FG, well then you might have a stalled fermenetation. But that's really not likely with an average OG beer. Hope this helps! If it is done, nothing wrong with that. Let the yeast clean up for another 2-3 weeks and then bottle/keg.