how to tell them?

I have been dating this guy for about 8 months now. 
I just found out I'm pregnant. 
I'm terrified to tell him, because I know he's no the kind to settle down for a baby. He is the type who never wants the party to end.
I don't want him to leave me. I know that he'll be there for our baby, but what about me?
My parents hate him. The think that he needs to get him life together. Even tho he holds a steady job.
Who do I tell first? What do I tell them?