Concerning drop +2

We’ve only been home testing for 3 days, but the drop at +2 today concerns me. How soon should I retest?

We’ve been trying to transition to low carb food gradually, though she has all but given up on her old dry food since I started offering the low carb wet. So she’s almost fully switched over in the last 3-4 days (I know, not ideal - I do have a hypo kit on standby). She’s still getting a handful of the dry in her morning and evening meals, but other than that she’s all low carb.