Wiped out

I skipped my 4 mile run on Thursday because my body was begging me not to run. I was going to make it up on Friday. However, at 4AM on Friday I got the stomach flu. I was in bed the whole day on Friday. It is Saturday now and I am not sure what to do about my 16 miler scheduled for tomorrow. I WANT to run but know that that would be STUPID. I have such a busy week that I am not sure where I can fit a 16 mile run in my schedule. I may do 5 miles tomorrow and try to fit in the 16 miler Tuesday morning at 4:00AM. I NEVER GET THE FLU. All of the books warn that when you start really pushing your body your defenses go down . . ..