Dark Red Heavy Bleeding

I’m 9w4d today, and randomly started pouring blood. No clots or severe cramping, just blood pouring out. I went to the ER and had a u/s done & we heard a heartbeat and baby is measuring 9w1d. They couldn’t find any reason for bleeding and told me to follow up with my OB tomorrow. Anyone else had this?? So confused and worried!

UPDATE: Saw my OB today & he said my cervix is still closed & it seems that everything’s okay. I’ve stopped the heavy bleeding & it’s just brown old blood now. I’m Rh negative, so I got the Rhogam shot early just in case that was causing the bleeding, but no definitive reasons.