LOL pugger. It could very well be true. I think she would still be giving off a smell or so e sort. Women have 28 days in a cycle, we're always doing something even though it might not be bleeding. Dogs could be the same.
My dogs humps others, and she's a girl, it's just pure domination. Unfortunately if the other dog owners aren't doing anything about it then it's going to keep happening. Can you go to another park with less dogs, if any?