Thank you for clarifying the matter.
I’m sorry to tell you, but unfortunately I don’t see an option how you can stay in Germany together in a long-term perspective due to your legal status.
Unfortunately none of you has a residence permit (a Duldung is not a residence permit - it only suspends deportation). If one parent had a residence permit, the other one could apply for an “Aufenthaltserlaubnis zur Personensorge” (it’s a residence permit to take care of someone → the child), but that’s not possible in this case since both of you have Duldung.
A baby that was born after its parents applied for asylum gets its own asylum procedure. But only if at least one parent is still in the procedure. Both of you already received a decision, that’s why I assume that your child gets Duldung too. So you two can’t stay here through the baby, as far as I can see.
Marriage doesn’t grant you the right to stay either because neither are you an EU citizen nor do you have a residence permit that would make family reunification possible. In your case it might even be a risk to contact authorities in this regard because both of you need to provide a valid passport in order to marry. Since your boyfriend’s deportation is imminent I wouldn’t hand these documents in.
Maybe the community knows about another option that I don’t know. But as far as I can see, there is no real solution to your problem at the moment :/
Still I wish you all the best.