Uterine Lining Shedding

I know uterine lining sheds during your period, but does anyone else notice it mid-cycle? It's not bloody or anything and it's not nearly as much as during my period. I'm curious if it's a sign of something else like endometriosis or if it's common. I don't have any other signs of endometriosis and there's zero pain/other symptoms with this very light shedding.