Two days ago my hen layed two eggs without shells while roosting but the eggs were in a sack. Today she layed an egg without a sack... just a runny gooey mess in the nesting box. I feed her layer mash, corn, barley, black sun flower seeds and oyster shells. Am I doing something wrong? Is something wrong with my Betsy? Please help... I don't know what to do to help her! should i giver her vitamins? Thank you... in advance for your help!