What is this? TMI

Does anyone know what this could be? Or maybe had a similar experience? The first picture is from earlier today and the second is from tonight. I had some pretty heavy cramps tonight at the store and it felt like I had passed something large so I came home went to the bathroom and seen that. My doctor said I could be having a miscarriage because of the bleeding ive been having. So I’m pretty sure that’s what going on but I’ve never passed something so large and I guess I’m just scared it could be something bad that wasn’t supposed to come out. What do you guys think?