I expect my nanny to tell me when she's too sick to work and take a paid sick day.
I can't afford to take a day off for every "might be a cold coming on," or "I'm still sniffly and coughing." If you come in, look pathetic, and wait for me to tell you to go home, I am going to be really, really annoyed. I don't know how you feel -- only you do.
If you're too sick to work, don't come to work. If you can power through on some Dayquil, please show up. Unless my baby is under 3 months old, I'll take the risk. They're going to catch colds sometimes.