I can't see a birth control method in this game, or way to get that? Maybe I don't want to have all my team pregnant. Is there something for this added yet? Or do I have to make something with alchemy maybe?

A successor to first Strive For Power game, currently at alpha stage · By
I think there used to be a Sterile trait you could, for example, give the MC.
I don't remember seeing it anymore but there IS contraceptive, which like many other things has moved to the Rules tab on the character roster list.

Used to need a level of obedeance to make servants take contraceptives IIRC but you can just toggle it now. Just gotta know where it is.