I have 2 chickens that are both 25 weeks old that haven't started laying either. The rest of mine have though. Give them time. They'll start soon enough.
There, there....no you aren't a bad person, its the chickens that are bad!
But one day soon (hopefully) we'll have first egg stories ourselves.
I took the laptop into the backyard over the weekend, while I let my girls out for some extra free-range time...I (of course) ended up reading some of the first egg stories. I finally turned the screen around so the chickens could see the picture of someone's first egg, while griping, "Do you see? Do you see what other chicken parents have today?!? But me....NO...no eggs in sight." and about that time a friend walked up, heard me, and suggested I seek counseling
Try some fake eggs or golf balls in the nests. I have read on here that if they see eggs then they think it is safe to lay. Mine lay in the same nesting box even through there are 4 boxes available. Also, one of my Amerucanas is still not laying and she is the same age as my other one. Keep an eye out in the run as well since sometimes they lay on the ground until they get used to the nest thing.
3 out of 4 of my girls started laying at 20 - 22 weeks, but Cordon Bleu the Blue Cochin is still holding out at 26 weeks. Her comb and wattles are smaller than the other girls.
I told her as long as she is happy and healthy, that is all I care about. She is my favorite.