Sorry to be ignorant

Kris

I've been watching a lot of birth videos for whatever reason (now I'm even more scared), and I'm wondering what's the gush of fluids that come out after the baby emerges? Is it just more amniotic? And where does the blood come from? Is it buildup from lack of menstrual cycles? Sorry I just wanted to get it straight and filmy research is not giving me definitive answers. Thanks in advance.