Want to live with boyfriend and my baby but dad wont let me?

i will be almost 17 when i have my baby and my boyfriend will be almost 19. my brother smokes with his girlfriend all day. my dad smokes too when hes home. i don't want to be around all this while I'm pregnant and then after i have the baby. my boyfriend has threatened to take the baby from me and go live with his mom if my dad wont let me move out before I'm 18. my boyfriend and i want to get married but not now. if i marry him and then can i move in with him after we are married? and he is getting a job in less then a month. he will graduate in 2 months. and i am currently doing online school to get my diploma. just because I'm young doesn't mean I'm still childish. i am very mature for my age and my boyfriend is too. can somebody please help me i want to move into an apartment with my boyfriend. neither of us want to be around dog hair and pot and alcohol and neither of us want our baby to be around that. i don't want my family to get in trouble i just want to leave and be on my own. im basically grownup already. always have been.