Possible Miscarriage?

I got my period two days ago, and it was unusually heavy. I had been off of the pill for about two months and just went back on it this week because I was having issues getting the medication. I just checked my period and a large solid oval-ish shape came out....was I pregnant? Did I just have a miscarriage? It was slightly larger than a quarter. I’m scared and I’m in college...is that really what it was?

Update: another large mass came out similar to the last...at this point I am pretty confident I’m having a miscarriage. How much more should I expect this is very traumatic