Replying to Bruise or something more serious

My day started off with a decently hard fall on our coaster box, nothing 2 serious, i got up and skied to the next rail in our park. about 3 hours later when i was fuckin around with some friends on our small hit i noticed it hurt extremely bad to turn my leg inside and lift it(like mute grab). also then inside on my knee is extremely tender and a lil swollen but theres no bruise (i dont bruise easly). But anyways im havin trouble determining if this is a bruise or if i torn something in my knee. Ive never had a bruise make it this difficult to move my leg.