Has anyone else experienced this? We had a good routine with my DS. Down to a single 1-2hour day nap at 11/12 then would go down at 7pm after dinner, bath and story. Now he's just not tired at 7. He was still running around the house at 10pm yesterday! No signs of tiredness, then up at 7:30am like usual. Same pattern emerging tonight. He seemed all settled then just started chatting, laughing and running around. 
We've had a big day too today, been out at a farm, played in the soft play and sand pit for hours.
Is this a stage? Will he sleep again soon?!