Orpington stopped laying

[ThreePumpkins]

I am a first time chicken owner, and I have one hen that stopped laying a week ago...

I have 3 hens, 11 months old, who began laying late December. My Orpington, Ladybug, struggled with soft shell eggs when she began laying, but has been a consistant layer since. Last Wednesday, after taking a day off, she laid a soft shell out of the blue. (It was broken in the nesting box.) They have access to oyster shell inside the coop, and I also gave them access to it outside since they are free ranging during the day. I have watched her visit the nesting box, but I haven't found any eggs from her. (She's my only brown egg layer.)

I have checked Ladybug all over and observed her, but nothing seems out of the ordinary. She has me worried. Is it normal for a hen to stop laying in the spring?

 

[Ol Grey Mare]

First thought is that, because you mention free ranging during the day, she may have decided to "go rogue" - she is visiting the nest boxes, but may be choosing to sneak off and actually lay her eggs elsewhere. How much of an area does she have for free ranging and what sort of cover is there in the area?

 

[ThreePumpkins]

I thought she might be sneaking off. They have a lot of acreage to roam, but I kept them in their pen for the last few days and still have no eggs from her.

 

[ThreePumpkins]

Just checked the nesting box, and we have a brown egg! I am guessing she was laying elsewhere...sneaky girl. Whew, feeling better.

 

[newmarch2014]

By Buffs and Prod. Reds are really "off" too. they have been consistent layers all winter (they are just over a year old and it was a really mild winter) then over the past week I am most days only getting one or 2 eggs. I have inspected their egg box to make sure I dont have an egg eater and I don't think so as it is clean as a whistle and they have hay in there so I would see some dried yolk I am sure. I am a bit baffled too. They may be starting to molt though. I have seen a few more feathers than normal and they are looking a little less groomed though still healthy fluffy butts.
By the way, my chickens hate oyster shells. They refuse to eat them so I feed them crushed up egg shells after they dry, they love them and I have never had an issue with them eating the eggs ever.
I do have a Buff that will hop in and sit on the only egg laid though it is not hers and I have to kick her out of the nest so I am wondering if it is a little bit of wanting to be broody, starting to molt, stress from the new chicks being introduced etc.