My leopard gecko is about 3 months old, and she was doing well until about a week and a half ago, when she stopped eating. A few days after this started, I bought her a different kind of food in case she just wanted to switch, but she wouldn't eat anything but a nibble from the new food. She's still drinking a lot of water, but she hasn't pooped in a while. Although she's been active - even more active than usual - I'm wondering if I should be worried, or if this stage will pass, please help!