That's the swelling probably you tore something. The sooner you have it checked out by a doctor, the sooner you will be skiing again. I don't get it, why wait?
If you wait, and begin treatment in a week, it will take weeks longer to heal.
If you wait, and your MCL grows back stretched out because you didn't immobilize it, you're fucked forever.
If you wait, and the pain goes away, and never see a doctor, but ski on the scar tissue of a freshly torn MCL, and you crash, you will take out your ACL and meniscus and will be out for 9 months.
Just a few scenarios to think about.