Hard start first thing in the morning

3 days in a row, first thing in the morning the truck does not start on first crank. I
let it go through the normal start up process and wait for the glow plug light to
go out, then turn the key. It cranks, but does not turn over. I wait for the start up
process again, and when the glow plug light goes out a second time, it will start.
No idea what is going on.