I am definately no expert but from what i have learned this year i would say it is not her pre lay yet, you still have awhile before your prelay shed comes. Im assuming she has been eating upto the point when you started breeding her and its just a growth shed, you can start feeling for follicles and see if you have any and would be able to make a guess whether she has ovulated yet, but would definately say that if you have only been breeding a week and this is her pre lay all the eggs will be infertile.