Snapped a pic of Yogurts underside because her vent looks puffy to me. And surprisingly clean?? Does it look swollen? I'm not familiar with sulcata bums...
I have tried for many years to correlate any type of swelling to pre-egg laying and have never been successful! Soakings is a great idea, it could be from successful breeding. The fact that you noticed a change is great and very observant.
I was out of town today but will do a soak in the morning. Just when I think I have them figured out they show me I'm wrong lol! I have been giving them soaks every week since i got them. She's still guarding her cave and gets a bit nippy and even tried to ram me when I took her out of it to put her inside for the night. Its been hitting the mid 40°F at night so I bring them in and take them out when it hits 70°. It was strange to me that it was a bit puffy but also that it looked really clean. She's still pooping and eating. They may have mated. Though I don't feel the need to bring any more sulcats into the world I'm pretty sure having "the talk" with them wont stop them lol!