First of course you need to have a custody order in place for the child and the new one when borned, Since most states will try and get money back from the babies fathers if they are not paying the requied child support.

So your first place is to start getting if you are not, child support on the first child, and also on second when born.

And no, your new boyfriend is not the father, the other man is the bio father and is to be held responible.