Here in Oregon though only way there wouldn't be a case # is in SD's sitch #1. If you both file together, then there isn't going to be a case # or stamp yet.
If he has already filed, then he has to have you served, and there has to be a receipt of that as well. And there would be a case # assigned and the paperwork stamped. Again, this is for Oregon.
If you don't have an L already, GET ONE NOW. The laws vary so much from state to state.