Baby kicking makes you feel sad, randomly?

So for some weird reason when I feel my baby kicks, I feel sad. And not like for a reason. It's almost like a switch. It's not because I'm sad they are in there or sad that I'm pregnant. It's this weird sad feeling that is connected to the kicks but not an actual thought or emotion.

It's hard to explain. It's like just the physical feeling makes me feel sad without thinking about anything.

I've heard some people get this with nipple stimulation and some other physical things, never this though. Has anyone else had this?