Plugged Duct - how quickly does it resolve itself?

ECT2012

So, I think I have a plugged duct - hard lump on my right breast which definitely just formed today. Makes sense, since I was away from my daughter for the first time today - I tried to keep up by pumping, but even when I saw her this evening she just seemed to be snacking and probably didn't empty the breast completely.

 I'm pumping now and plan on pumping again before I go to bed around 10 - any idea how quickly these things work themselves out? Is pumping or nursing often the best way to make it better? LO has been sleeping really good stretches lately (knock on wood...), and I'm hoping to not have to set an alarm to get up and pump again tonight!!

Thanks!