Strange going on with my chickens egglaying

they may be laying in the wrong place-

they can move eggs if someone is broody.

squirrels can eat chicken eggs...

check for hidden nests!

They might have just all taken a break at the same time.

They are not machines. Bad weather, etc... can effect them.

Just do a general heath check. Make sure their crops are full at night, no has has abnormal poo, or mites or lice. 

Even young healthy hens will not lay every day/every other day for months on end. They do take breaks. :)

Mine bury their eggs deep into the nest.  When it looks like I didn't get many eggs, I have to dig deep into the nest to find the rest of the eggs.  Even then I miss some.  I will find the ones I missed when I clean out the coop.  The deep litter method gives them plenty of places to dig deep and 'hide' their eggs.  Guess they're tired of me coming in everyday and taking their hard work.  The funny thing is that none of them will 'sit' on a nest - so I'm not quite sure why they hide them.

For a few weeks last summer I didn't get a lot of eggs - I wasn't too worried as it was the first summer my hens were laying so I thought their bodies were still adjusting.  I was doing some gardening one day and came across 2 dozen eggs in a nest under a thick bush.  Locked them up in their run/coop for a few days and left a few eggs in the nest to get them to realize that the coop is where they need to lay them - no problems since.  If they free range is it possible that they may have hidden nests somewhere??? It is spring and instinct to 'protect' the eggs may have kicked in.

As previous posters said - some hens take 'breaks'.  It seems that I have a few hens that lay an egg every few days and I have some that seem to lay almost every day.  I have 8 hens and get anywhere from 4 to 8 eggs a day.