It usually lasts for a couple to a few weeks. She may be laying eggs a few weeks after the receptive phase ends. She’ll get plump and even lumpy looking and may slow down a bit. She may start exploring lower in the enclosure as she looks for a good place to lay her eggs. Some chams stop eating a day or two before laying. Once you see her digging, cover the lower half of the enclosure and make sure she doesn’t see anyone. When she’s done, all of her tunnels will be covered, she’ll be thin again and she’ll be sitting in her favorite branch waiting for food. It takes a day or two from start to finish. If you need more info, just ask.