2000 sunfire 2.2 engine won't start

3 weeks ago it ran fine. I parked it for 2 weeks, went to start it and it wouldn't start. It was below zero so I figured gas line froze. (It did have spark) Pushed it in a garage with heat and it started right up after warmed up in garage. Had 1/2 tank of gas, but went and topped it off anyways. Drove it for a week. Parked it at 3pm sunday and monday at 8 a.m. wouldn't start. It was in the teens for temp and 20's+ since then. I doubt its a frozen gas line.... what next???? I do hear the fuel pump kick in.