Yeah, I think you're right. And I could see the pill messing with Natasha's Red-Room wrecked hormones, so she's not on that, and she and Clint are both clean, so why bother using birth control and....oops. FOUNTAIN OF LIFE.

As far as kid!fic goes, I can see them maybe adopting a kid if it comes through comic book circumstances or whatever. And I could see them doing whatever they can to make sure that kid has the best life possible. Personally, I'm not gonna write it. I've got a massive kidfic series going on in another fandom and I'm usually not all that fond of kidfic to start (yeah, I don't get it either) because a lot of the time, the kids usually have looks that come directly from their parents along with the parents' skills, the parents have Dead People Naming Syndrome, or, I don't know, I just feel like too much of it messes with my ability to suspend my disbelief.

But I do enjoy a well-written kidfic, I will admit that. :)