sluggish start up

[scoobopdan]

This problem has started out of no where and isn't too much of a concern, but I'm interested in what the rest of you think and if anyone's experienced it before. The outside temp and humidity hasn't changed and it doesn't seem to be performing any differently. When I start the car up, starting about three or four days ago, it's just really sluggish. It will turn over and start just fine but at a really low rpm like it's asking to be pumped. After a second it will come up and be at where it should be idling. It's a slow rpm at first, but smooth. So the car doesn't shake or shutter or anything.