12 weeks and 2 days heavy bleeding

I’m 12 weeks and 2 days pregnant. I was feeling normal, no cramps, nothing. I wear a panty liner for discharge. I used the bathroom and my panty liner was soaked with bright red blood, used the bathroom and felt clots coming out. After I used the bathroom I started getting cramps, lower left side of my stomach and my lower back. Also when I sat down I felt a weird pressure/pain on my butt. I went to the ER, they did an ultrasound and Pap smear, also took blood. I did not see the ultrasound or hear the heartbeat. But the doctor told me the baby is measuring what it’s supposed to be, there was a heartbeat, and my blood levels are accurate to how far along I am. The Pap smear he seen “no active bleeding, but he saw clots” He recommended I follow up with my obgyn asap, and could not tell my why or give me any reasons as to why I could be bleeding like this. My obgyn could get me in on Thursday the earliest. Did this ever happen to anyone?? Was baby ok or did you end up miscarrying?? I’m so scared and been heartbroken thinking I’m going to miscarry.