Spawned at world spawn instead of bed

I died in the Nether which then spawned me back at my bed. 

I quit the game and then 20mins later I log back in and I'm at world spawn (4000+ blocks away).

The game was on peaceful so there's no chance i died after respawing at my bed. 
I live alone, so nobody could have logged onto my game and affected my spawn location/game somehow.