Puppy always excited “pees” right before going out.

We’ve been going to her potty spot every hour on the dot. Right before it’s time to go outside she wags her tail crouches, rolls over and a tiny bit of pee always happens. It’s the only time she really pees in the house now, we are almost trained with occasional accident. But I’m not understanding the situation excitement pee. I say it in quotes because it’s literally the smallest amount. It’s like she leaks.