2002 Ford Explorer no start

2002 ford sport track. Vehicle has been running fine. Last week turning the ignition to the on position I noticed that I did not hear the fuel pump prime. I turned the key to the start position but, it would only crank. Pulled the key out & turned it again to the on position, the fuel pump primed. Cranked the motor & it started ok. Been driving ok!
I drove the car to work & home last night, every thing ok. Went to start it today, I turned the key to the on position did not hear the fuel pump prime. I cranked the engine but would not start, tried several times, not even a sputter. Shot some starting fluid into the intake, still would only crank, not even a sputter. No smell of flooding. I did not check for spark yet. The outside weather is a high of +10.
last week the weather was also cold on the day that I first had a problem. Thinking about the fuel pump relay? Or the securilock antitheft. I did try a spare key, no luck!
Thanks, Al