DORTMUNDER EXPORT

did a Dorty back on January 3rd, and it is still fermenting (and nicely) but it is going on 14 days and I am afraid I may get a bit of off flavor if I continue to let it go.
I used a Bavarian lager yeast (2206) and have it at 55 degrees.
Funny thing is there is plenty of kraeusen but no venting coming out of my air lock.
The smell out of the airlock is really nice, so i don't have any crud in it. But I was wondering whether any of you fine folks have had the same issue with long ferments?

I've done a Dortmunder Export and at 14 days I didn't expect profuse bubbling in the airlock.  On mine at that time there were probably just very tiny air bubbles around the top of the starsan.  I'd rock the carboy lightly once or twice side to side to stir up the yeast a little.  I have fermented all my lagers 18 to 21 days and never had any off flavors.
Just my opinion.

Just bottled it today. Looks smells and tastes like a winner. Bottle conditioning at 50 for 30 days.