Anyone's pup weird about going pee?

This happens maybe half of the time I take her out..

It's 830am, she hasn't peed for 9 hours. I know she has to go. I walk her to the grass/dirt patch right outside my places front gate. She walks around for a couple seconds then looks at me and cautiously sits down.

The look she gives me also looks guilty, or scared? I've never. Ever. Been physical with her. I have always used positive reinforcement training. But she legit looks scared of me. Then I walk her around the corner to another patch of grass and she immediately squats down and takes a normal morning pee.