They both go into the nest

And last night I found the hen missing from the perch. She must have been in the nest.
But normally, the hen isn't in the nest at night except after laying about 5 eggs.
And during the day either the hen or the male is sitting in the nest.
. . . but there are no eggs...yet

I don't know the age of the hen.
I'm confused where they are in the mating process.