Im so confused

So I started my period today. I went to the bathroom and got the gnarliest blood clot, but it didn’t look like a blood clot. Normally mine are dark red and look....well like coagulated blood. This was purple and had a vein. I called my mom to my bathroom and she said it looked the same miscarriages look when she’s had them. BUT I haven’t had sex in 7 months and the last time I did we used a condom and I’m on birth control. Plus, I have had my period pretty consistently since then. My mom said it’s unlikely but it could be linked to endo, which I have family history of. We put whatever it is into a container just in case my gyno could do tests of it. I called and left a message for him, and the nurse called back a little while ago. She said he thinks it’s a decidual cast. I looked it up and it looks NOTHING like what came out of me. My mom thinks I should call my doctor, but I don’t want to look crazy. What should I do?

I didn’t post a pic but I do have pictures.