3 weeks to go!

I have less than 3 weeks to go and Dan is now ill with serious man flu. I keep thinking if I get a cold now I can probably get rid of it in time but then how much will it take out of me for running a marathon? I could maybe get away with it for a 10k but not so sure about 26 miles! I'm dosing up on lots of vit C and echinacea. He has also been banished to the front room!

Why now? He never gets ill.