Can the foster care system take away my unborn baby if I runaway and get caught ?

OK so Im 17 and 4 months pregnant and very unhappy without my fiance ( the father of my unborn child)... And sadly emancipation is not an option for me.. And I really don't think the courts will approve of me getting married .. So here is the thing I lived with my fiance at my grandmothers house and since she didn't like me having a baby and not giving it up she kicked me and him out me to another foster home and I live in elk grove ca and he lives in sac 2 hours away.. I need really need to know if I runaway can they take my baby away when he or she is born if i get caught?