Large blood clots

Hey everyone this may be tmi for some people. I have extremely irregular periods and am usually very heavy with lots of clots but this was way more than usual. I just started today and I had a little more severe cramping than usual and then in the shower I passed a clot the size of my palm and then another literal handful of dime to quarter size clots. Does anyone have an experience similar with a clot that big? Did you find out what caused it?