About to Pee My Pants

Stoked to be three sleeps away from running my first ultra marathon!  I took a week off to rest my knee, consulted a physiotherapist as well as my doctor.  I am fortunate to have a doctor that runs ironman triathlons.  Got lots of running advice as well as medical advice from him.  He told me if my knee deteriorates to a limp during the race to call it quits.  Not sure if I can do that - I am stubborn enough to finish what I start.  However to hear it come from someone who understands the training effort and excitement of the event and damage that could result - it weighs more heavily on the decision.  As a result, I was really bummed out about the knee situation, how it felt and having to rest it for a week.  Yesterday I ran for an hour and fully expected it to swell up like a balloon afterward.  It felt a bit nasty for first half hour of the run - meaning I was really getting down thinking I would have to make the call to not race.  If I couldn't do an hour without soreness how would I do 10 hours.  Then the strangest thing happened....my knee started to feel better, and better and better.  By the end of the run it felt strong and pain free.  I tried to reason in my head that it must be inflammation starting thus reducing the grinding and pain from grinding.  However I waited for it to swell and it has not.  I do not understand what is wrong with the knee.  Very strange.  When moving about throughout the day, I feel sharp pains every so often in the inside of my knee but to walk up and downstairs it doesn't hurt at all.  Anyway, I don't care why or how it feels better - I just care that it does.  Now I am crazy excited about the weekend!