Bleeding clots , not on period

J

I had my period from the 16th-20th. Now I’ve been sitting on the toilet all morning cause I’m uncomfortable & keep passing clots. Has this happened before to anyone else ? Or does anyone know what it could be? I want to go to the ER cause I’m scared , but I know they’re busy and I don’t want to waste their time. I just moved to a new state and don’t have a primary doctor yet.