Exercise- a surprise?

I’ve never heard of this but it’s happening to me.

I am 7 months pp and I just recently started getting back on the horse and trying to work out. It’s been going well, I’ve just been having something really odd happen when I do.

Sometimes it feels like I REALLY have to pee. Like all of the sudden. Almost like I’m aroused? It sounds insane but can someone let me know- is this normal? Am I just messed up? Is my pelvic floor just SUPER weak?