If you still have a lot of chest congestion, I'd probably wait to resume exercise until it clears up a little more. Trying to push yourself while you're still recovering can delay the recovery process even further. Even if you aren't able to run the entire 10K, you should still be able to finish even if you have to do some walking. Just listen to your body and try not to push it too quickly.
"You may have a fresh start any moment you choose, for this thing that we call "failure" is not the falling down but the staying down." Mary Pickford
"No matter how slow you go, you are still lapping everybody on the couch."