Airlock's are an unreliable guide to fermentation activity or completion. If there's a leak they won't bubble at all. The only true way to know if your brew is ready to bottle is checking the gravity (with a hydrometer). If the gravity reading is the same on 2 consecutive readings at least 24 hours apart it is ready to bottle. Time is no guarantee that fermentation is complete (although after 2.5 weeks it is probably done).