2004 Chevy Cavalier car won't start

I filled up at a service station I don't usually get gas at. My car ran fine until later that afternoon the temperature outside dipped into the low teens. I picked my son up from school and the car was shut off for about 20 minutes when I got in and turned it on it hesitated to start I fluttered the gas pedal a bit and it ran fine it from then until my next stop. I stopped by the local laundry services for about a half hour and the same thing the car hesitated when it initially started up and then ran fine. I thought that I may have bad gas so I got a bottle of heet and put it in the car and came home. I went out later that night to see if the car was running better this time when I tried to start it. It started for about a minute hesitated like before and died. After that it quit starting the temperature today is in the low 40's so I figured if the gas line was frozen that it should have thawed out enough to start it. At first it start and ran fine for about 5 seconds before dying again. Im wondering what could be causing this. The car has ample spark and up until now showed no signs of a bad fuel filter or pump.