Bubbling is not a sure fire indication of fermentation, it could be simple off gassing. I would wait. Leaving it on the yeast will only help the beer clean up. the secondary is not a fermentation vessel but a clearing vessel. Now would be a good time to check your gravity. Unchanged gravity for 3 consecutive days is the sign that fermentation is complete. I primary for 3 weeks and don't check gravity until then. Fermentation is normally complete within a week, the additional 2 weeks is for the yeast to do there side job. Think of it like this, if you hired the yeast to do your lawn and they didn't weed eat or sweep up, is your lawn done?