Dry hopping and fermentation

I've got an American Bock ale with a plug of... can't really remember what in the fermenter (it's an old recipe kit I found last week). I'm wondering, though: how long should I keep it in the secondary fermenter if it's being hopped as we speak? It's going on 3 days and I don't want to overdo the hops because I like the malt flavor from this one and it's worth preserving. Should I just wait til fermentation dies down or what?
Sorry for the lame question- this is one of my first attempts at 2 stage fermentation.

I generally don't dry hop for more than 10 days, on average I shoot for 7 days. If it tastes too hoppy when you crack that first one, then let them sit for another 2 weeks, the hop aroma will fade with time.