Has anyone experienced this?

My belly button keeps getting sucked in very rhythmically starting from quarter inch right underneath the belly button and slowly pulls in the belly button to like quarter inch above belly button. It takes about 6 seconds and happens every 15-30 seconds. It doesn’t hurt... just have a weird tugging sensation....

I am not on my period...

I gave birth over a month ago...

I didn’t eat anything that would make me gassy...

I went to the bathroom to see if that would change anything but nothing changed...

So confused 🤷🏻‍♀️