I'm new to the reptile world - I have a male/female pair of thick tailed geckos (underwoodisaurus milii) in a 60x45x45cm tank. They have never been aggressive towards each other, and I've had them together for about three months. The male has always been the smaller one, but in the past few days I've noticed the female acting strangely. She has been digging around in the sand a lot, which I have never seen her do before. Just making large mounds of sand in random places. She has also faded in colour a bit, (she's a beautiful orange colour), and her tail is definitely a lot slimmer than it used to be. She still comes out every night but I haven't seen her eat recently, though I have not been checking regularly. Her abdomen is still quite fat though. I have considered the possibility of pregnancy, but I don't know what signs to look for. Her last shed was ten days ago. Please help - I'm not sure if she is sick or perhaps even pregnant, since I have so little experience with these guys.