Just got first period and found Tissue

Tina • Married the love of my life and he gave me the best gift in life, our son Logan.
FTM: Got my period Wednesday after 10weeks and today I found two pieces of tissue like clots  in my pad. At first I thought it was blood clots but they are rubbery and like raw meat. Is this leftover placenta tissue? They were the size of a quarter. Has this happened to anyone else?