Could be a lot of things...
How well does your boot fit? When it's on do you have any heel lift or movement?
:Maybe. But i will check that incase.
Landing backseat at all?
: I don't think so my friends say i land pretty good and not in the back seat.
Have you had a really hard landing lately? Onto boilerplate or something like that? Case a jump?
:Maybe that's it? But is there a like pad i could use?
I would imagine it's just bruised. It happens. Take it easy on it for a little and get back into jumps slowly.
:If so... How would i know? Will it look like a normal bruise?
If it persists or gets worse check it out with a doc. The extreme possibility is that you might have a bone spur. Or you're on the krockodil.
Ouch i want to go skiing tomorrow though i don't think i will hit jump if it can be that serious...
I'm just firing off ideas.