Heavy bleeding with no pain. Anyone ever experience this?

Alfonsina

Mon afternoon I had intercourse with my partner. Early Tuesday morning I had a brown discharge. Later on that morning, I had a internal ultrasound, and started bleeding heavily 2-3 hours later. I filled 2 pads in the course of 6 hours. I also passed 2 golf ball size clots and had small clots when wiping. I had no pains or period like cramping. Went to er and they said I had to wait it out. Today (Wednesday) the bleeding decreased a lot! Still bright red, but very little. Still no pains or cramping.

My hgc levels said im showing 3-5 weeks pregnant. I go back Tuesday for another blood level test and results and Dr appt next Wednesday.

Has anyone ever experienced this? Or know anyone who has? What may have caused this or what is it?