Pls take 2 mins to read this n leave advice!! Pls!

I'm 23 yrs old I'm in school and work for a mortgage company. I have an ex I was w for 3 yrs, it was a very rough relationship and we recently broke up and he moved in w his BM of his 7 yr old daughter due to living situations. We have been apart since July he moved in her in August. For a while we were still having sex and decided to stop abt a mnth ago cause the situation was gettin to... Complicated. Today I found out I'm pregnant. I love this man a great deal, but hv always had my mind set on marriage before kids! I never even wanted kids cause I was so scared of becoming a single parent and forced to raise my child alone. it's my worst nughtmare! So now I'm stuck between these decision of what to do. When I ask him what he wants he says he doesn't know, and that he knows this is not what I wanted...cause someone pls help me.