A very hard bang on the kneecap

I tripped and fell while running the other night and landed hard on one knee. Since the rest of me landed on gravel I think the top edge of my kneecap must have hit a pebble, because a chunk of flesh was removed although there wasn't any damage to my tracky bottoms. The wound has now dried up and looks quite healthy, but it's at the centre of a swelling which covers all the top of my knee. I've treated it so far with Nurofen (orally) and Savlon (rubbed in) and it seemed to be going down but now it's swollen again.

Is this normal for this sort of injury? Will I damage it further if I run? It doesn't hurt inside and my knee works fine, it just feels rather like when you have a large blister, i.e. the skin feels tight and it's a bit hot.

Advice needed urgently - I've got a 10k in 2 weeks!