I am convinced that gravid female chams just love to mess with our heads. I also agree that deremensis seem to be incredibly stable despite low appetites sometimes. Not that it's good to do, but maybe they are just more stubborn than most species. Pigheaded comes to mind when I think of my male. I wondered if he moved from one spot for entire days at a time. I suspect they have a preference for insects that we simply don't offer (like lots of small flying or crawling things that are hard to handle). Some chams seem to change body "bulk" daily in response to humidity I suspect. The best way to check her gravidity would be to weigh her. The developing eggs should increase her weight despite her look.