Why should you only be able to
phone in sick? If you're feeling miserable you might as well be at work anyway.
What about all those days when you wake up, the sun is shining, the sky is blue you feel radiant and there are a million things you'd love to do and none of them involve work? Why make yourself miserable?
It is possible to get away with this, sometimes, people get confused when you ring up and think your phoning in sick anyway. Go on give it a try you know it make sense.