Probably off topic but does anyone even discuss the whole kids/no kids/gray area dealbreaker at all? It's not just for people planning on marriage (marriage isn't the last step/ end-all be-all of a relationship for everybody). Because then you'd have an idea beforehand.
And tbh it sounds like she either oopsed him or got pregnant early (if that was in the plans anyway) for the purpose of eventually kicking you to the curb. Babies aren't bandaids, I don't see anything good coming from this.
Sounds like shrew behavior and that's not going to end any time soon.