I've had this happening to me. My T disappeared for like a day. I decided not to be the one contacting T and waited until she found out.
I completely understand your fear and not wanting to go into thinking it was an emergency, etc.
Actually the only thing that will give you a clear insight would be to contact T and find out what happened. then you're free to decide on what you want to feel and think about it. But until you know for sure, everything will just be based on speculations. And I don't think that's always a healthy thing to do (at least not for me).