It speaks well of his character that he wants to be around for the mom for support in the grieving time. Even if it was an "Oops!" they created life together and it is done. So a observing a decent mourning period is the decent thing to do.
He doesn't have to hang around forever there, but he doesn't have to make it be like "Slam, bam, thank you ma'am!" either in their lovership that led to an unplanned pregnancy. Parting seems inevitable there, but wanting to part on decent terms at a decent time is commendable.
Timing matters in things.
A right time and right place for everything, and everything in the right time and place.