depo injection

Iv been on my period for 26 days now and recently iv been getting really bad headaches something came out of me earlier in the period but I thought it could of been uterus lining but I took a picture and posted it on here iv had people saying it looks like a miscarriage and people saying it could be an organ etc I'm really confused but I hate going to th doctor anyone know what could be happening I'm 15 currently on the depo injection next one due on 29th December Picture below of what came out of me