Had a good week and then sick again

Last week and the begining of this one were great. Got all my workouts in and was feeling really good. I've knocked off 1 minute of my per mile pace in the run and 20 seconds off in my per 100 meter swim. Then, woke up Thursday feeling like crap. Sore throat, stuffy. No swim, no bike. It stinks to feel like I'm getting aheasd and doing well and then something happens. 

I spend way too much time around babies and other people that are constantly sick. I have had about 4 colds since January and they always kick my a#%.