She has apparently been married to him for several years, so it's unlikely the first time she was "impregnated" by him. She implies elsewhere that she terminates the pregnancies every time she gets pregnant by Moyupu, by pill or abortion, because she doesn't want his kid and never did. It's annoying as hell that Japanese authors don't explicitly state these things more often, they are addicted to being vague even when the manga is this explicit about other stuff. It's a really annoying trope in Japanese manga writing.
ALSO, a lot of people are confused, so here is an important note:
This isn't the End, despite the name. There is one more chapter coming. Author states this on Twitter himself.