Are they new layers? New layers or Hens coming off of molt will lay rubber eggs. IF not, collect some of that fresh morning poo and send it in for a test to see if there are worms in the flock.
They are 27 week old pullets. 3/6 are laying. I thought perhaps it was the third brown egg layers' first eggs? I wouldn't be able to see the worms? Where would I send the poo?
