Serious question for folks - how exactly do you imagine these pregnancies working?

I love worldbuilding settings where the population can be 100% female - or there's like a race or faction that's all female - so having women able to reproduce and make new little girls is really nice to include.

If it's fantasy, I'm not averse to just saying it's something they can just do via a natural sort of magic or what not. Women just being able to temporarily become futa for reproduction is another option - but I know futa is a no-no on this board.