I am hopping someone recognizes this one; again searching for someone else this is what the person remembers:

Cas is omega or mpreg.. Castiel is in an abusive relationship with Dean.. they have a baby daughter, and Cas is pregnant with second child. When Cas was finished with the doctor appointment he was waiting for Dean to pick him up but Dean wasn't there so a pregnant Castiel had to walk home carrying their baby girl through the rain.

Thank you!