I'm not sure if this is a bug or if I just made a mistake, but I can't find Nick Valentine anywhere. I don't remember which settlement I sent him too, but I've checked all of them exhaustively. I built a bell at all of them and used it, but he still was no where to be seen. He's not at his office either. My next main story quest is the Glowing Sea, so I don't think he would be waiting for me anywhere for a quest either.

He's my favorite companion, so I've been holding off on doing anything big until I can find him.