My veiled Cham has eggs which are infertile. The vet told me to put potting soil in the bottom of her cage and put about 2 inches thick. She is digging but has not laid any eggs yet. The vet said she should lay in about two weeks. It has been a week. Everything I see says to use play sand and put them in a container about 12x12 and 8 inches deep so they can dig a tunnel. How long does it take for them to lay eggs normally once you start to see signs?