when to run

I injured my leg about 3 weeks ago whilst training for a half marathon. But it has started to feel better and can now jump and run on it without any pain, but it seems bruised when i touch it . The half marathon is this Sunday and really want to do it. Should i leave it, to let my leg completly heal up? Or should i risk it and go for it after months of training on my own ? Im really stuck on what i should do dont want to end up with a bad leg again but really hate the thought of not joining in with the half

Personally I would attempt the race as long as I have no pain with 24 hours of the start, but if you feel any pain during the race, no matter how small, STOP!