Bubbles mean nothing at all. Fermentation is not done until gravity readings are stable when talen two days apart.
Even then, you may want to leave the beer for a few days more, to allow the yeast to metabolize any byproducts and thus clean up the beer.
A lot of the vets here tend to go with three week primaries, no matter what the recipe calls for.
Hopes give you no sugars - which is what affects gravity, so dry hopping has nothing to do with gravity. Sugars come from grain, extract, or some adjuncts (table sugar, molasses, honey, etc).