[wonderbread]

Well if noone else in your family knows, like those that would be supportive you need to start telling them because you need to start thinking about what to do.
Think firstly what it best for the baby and you. You are twenty and would be a single parent if you do decide to raise the baby. Do you have a strong enough support team to help you and do you even want to keep it.
Secondly think about adoption if you have thought about it and feel like it would be best not to keep the baby.

As far as your boyfriend leaving, I am extremely sorry. I can't imagine that. But he is a man and most get freaked out about things like this. They feel like their life will be ruined by having a child. But the thing is, no matter how far they run they will always have a child in the world that is theirs. Maybe he just needs time to sort this out on his own. But there is the possiblity that he just doesn't want to deal with this problem and make it yours. But the truth is, he now has a responsibility. Even if he doesn't feel the same for you or care about you ( I am sorry for that too.) he has a responsiblity to the baby. So if you decide to keep the baby you can take legal action towards him so he can help provide for his baby.