Pregnant but it wasn’t planned!!!

Im 17 and I’m 28 weeks pregnant. I went to the doctor with a friend when I was 9 weeks. They took my blood and did an ultrasound everything looked perfect. My boyfriend left when he found out because he didn’t want to support a child this Young even though he’s 21 and has a stable job. (selfish) After my doctors visit my mom received a letter from my doctors office and I’m not sure what it said but she came in my room and threatened to kick me out if I was pregnant. I have hid my pregnancy from everyone because I honestly have no place to go if my mom kicks me out. I got a job a month ago as a cashier in retail but it’s not going to be enough to get a place and raise my baby. I’m so scared right now because it’s getting to the point where I can’t hide it anymore. I need advice and please do not hate I know I should of been going to the doctor and that’s my fault I’m just scared of what my mom would of done If she found out.