Night time

[playthegame]

My 4 year old has been day time potty trained for well over a year. Night time was hit and miss until about 4 weeks ago. Has done 4 weeks with no nappy at night and no accidents.
However on Wednesday he started school and has for the last 3 nights, wet the bed. I'm not sure if it's just because he is super tired and sleeping deeply or something else. He usually does not wake for a wee in the night, just sleeps through and does a big wee in the morning.
I don't know what to do really. He's done so well up until now. I do not want to go back to nappies at night but also don't want to be stripping and changing beds at 2am! He currently co-sleeps so am having to change a whole double bed!
Should I just persevere or try again in a few months?

School is so unsettling for them, it's not surprising.

Can you put him night nappies just for a little while until he adjustes?

Or you could do the double sheet thing.

So wee pad, sheets, another pad, another sheet.

Depends if the duvet gets wet too?

Thank you.
I didn't think about the double sheet thing, I'll give that a go.
On the plus side, we had a dry night last night.