krausen after 2 weeks?

I just brewed a blue moon clone (ag). I used wyeast belgian wit yeast, first time using it. Has been fermenting away for 2 weeks at about 67 F. I popped open the bucket today for gravity/flavoring sample and was greeted by a layer krausen still floating on top. Smells fine, took my sample and it tasted fine gravity was 1.012. I am not too worried about it but I was wondering if this normal for this yeast or wheat beers. I am used to my krausen dropping out after a few days.

It's normal.

Which Belgian yeast? I had WL300 do that both times I used it. No big deal, it will drop soon.

even if it never drops as long as you have your final gravity you can bottle.

My wits with bottle harvest hoegaarden yeast averages about 3 weeks with krausens, even though the hydro readings show terminal gravity has been reached.