Any thoughts on my knee pain

So yesterday I was skiing at A Basin. Enjoying the wind blow powder and rallying through the land of the giants hopping off rocks, having a great time. Landed a ten footer in a flat area, butchecked, skied out, stood up and felt pain in my left knee. Fell over.
Sharp pain for 1-2 minutes, then skied down to car, went to work. Small amount of swelling, but not for a few hours after injury. No pain excpet for when I try to bend knee to 90 degrees or past.

Its the next day and there's a small amount of swelling that I'm managing with ice. My case seems to be the classic backseat ACL deal, but wouldn't there be pronounced swelling and instability (I feel strong in the knee, some pain when twisting on one leg).

Any thoughts are appreciated. Thanks!

God, I hope this will go away - we're having the best winter in years - damn flat landings!!