Getting a cold?

It's less than a week now until London (thank goodness it is almost here!). Unfortunatly I am not feeling great today which is a worry. I ran the XC yesterday but my legs didn't really fancy it. I put it down to a late night working on Wednesday, late night out on thursday and very early start on Saturday morning as I had to go to work then too. However, when I woke up this morning I still felt tired and pretty bunged up...looks like I need to remember to look after myself this week!