>>38145133It's reasonably to assume they do, but in the games they had this "kid franchise" thing where you put two Pokemon together on a daycare and for "some reason" an egg appeared and the people over the daycare don't know what to do with it and just give it to you.
That said, the current games just ditch all of that and your Pokemon just give you an egg because you gave them a sandwich or some shit. (I haven't played them yet)