1998 Saturn SL2 leaking coolant

We just bought this little saturn, and after we drove it 2 times, we noticed that it dumped the coolant in the driveway, then the low coolant light was flashing, we added more coolant, then it happened again, but not all at once, it leaked out over about a 12 hour period of time. It does not seem to be coming from the radiator area, more like the area of the coolant overflow holder. The problem is the car never overheated. We thought it may be a bad hose, the water pump or the iar conditioner, since the previous owner just replaced the a/c compressor a couple months ago. Any suggestions on what amy be happening?