That's not wise - your cider will need to produce a lot of co2 to stop itself becoming infected. You won't get much bubbling because that happens when you run out of room in the bucket and the cider starts pushing co2 out of the airlock.
Rack it off as soon as fermentation has finished, don't give it any more time in there than it needs. It's a slow fermenter so you're looking at 3 days for visible signs. In the meantime, don't open the bucket or you risk infection!
In future, use demi john, or you can use a 5 litre water bottle if you sanitize it.