My best guess is that she is building (growing follicles in order to be ready to breed), but checking temps just to be safe is a good idea. I would do is get a tempgun different from what you usually use to check your temps in case this sudden behavior change is from increased temperature raising metabolism. She looks pretty thick throughout, rather than just where she would have eggs or follicles, which is about 1/3 from tail rather than right in the middle. Right before going to the bathroom, it can sometimes look like there is extra weight in that section too, so even then it's not 100% sign of anything.
If she were gravid, she would likely be heat seeking, cool seeking is more while building and during ovulation. Has she been cool seeking more before this week or is that new?