Did I miscarry or is this just lining/tissue/desidual cast

Natalie

So I was a week late and I finally got my period around 2pm today. Bright red, cramping. I went to the bathroom before bed to change my tampon. For some reason I couldnt get it in, so I stood up and this fell on the floor....... please help me figure it out. Looking online I see other pics just like this saying it’s a miscarriage, but who know if a doctor told them that or if they’re just assuming.