Dear
@Kwaku,
thank you for your question.
The best thing to do in your case, is to get a Vaterschaftsanerkennung und Sorgerechterklärung from the local Jugendamt and then ask the Lageso to move officially to your girlfriend, who is pregnant with a child from you.
I hope I could help you, if you need further assistance please let me know.
Best regards,
Nilab