pain through the side of your knee isnt good. it'll lead to stability problems. without knowing more about your condition i cant really say much else, except that there might be an imbalance of strength between your medial (inside) and lateral (outside) quads, causing your knee to pull one way slightly more than the other.
the other possibility is that you tweaked the lower half of your leg to one side recently. im guessing the pain is on the inside of your knee? that means the ligaments have stretched slightly. ice is good but the only way to fix it is time off skis. cycling might help to correct the balance issue and its good because there's no impact.
just dont ignore it. i had a patellar realignment (tibial tuberosity with medial reefing and lateral release of the quads - google it for good images) in november. not a nice experience and i really dont recommend it. after the several times i dislocated my knee cap i got that same pain on the inside of my knee. it was due to the lower half of my leg moving outwards. not nice. im mostly recovered now, although there's massive muscle wastage so i need to spend a lot of time on the bike.