(TMI) I’ve never had this kind of clot please help!

I called my ob and sent her this picture but she passed it along to a mentor so they could get a better look. I’m currently on the Mirena and have been for a few months. So my period has been super irregular, In other words I feel like I’m constantly on period. Which the ob said is normal for the Mirena implant. But then today I had this and I’ve never seen anything like it before, at least not from my own body. Does anyone have any idea what it could be. I got a negative pregnancy test.