Kitten backtalracked on litter training

Im at a loss!! My kitten (found at 5 weeks, now apx 10 weeks) started off well with her litter training, and now will consistently go next to the pee pads that she used to use without a problem. She had even started using the litter box properly and no absolutely will not.

Anyone run into this before? She wont even go on the pee pads, its directly next to them.

Vet visit is Saturday for her first checkup, but this is clearly a behavioral thing not a health thing that i dont understand.