I've broken my left collar bone twice. The first time it healed perfectly. The second time it didn't. Instead of a straight line it has a slight up arrow shape. It's weaker also. I think there's a calcium deposit on the part of the bone where the break was.
Anyway, you should be OK to lift weights in about 7 or 8 weeks if you wear the brace and don't push it too hard too soon.
Hurts like a beeyatch don't it?