My chickens started laying but stopped again,why?

[Firsttimehens1234]

My 3 hens just started laying again after their winter break.
They layed constantly for the last month maybe even when we got a cold period.
But now that haven’t layed all week and I have looked everywhere in the coop to see if I can find any and they just don’t lay.
Why is that?
They have plenty of shells and food all day

 

[nuthatched]

It's normal for laying to be spotty after the winter break