TMI ** TRIGGERING ** miscarriage

Idk what happened. I didn't have any cramping or definite spotting. Nothing. But last night I was sitting down and i started to feel like i had just started my period ( not pain but the feeling of a pool of blood gathering) so i stood up and felt a big gush of what i just knew had to be blood. I immediately went to the bathroom and used toilet paper to determine that this fluid all over my underwear was indeed blood. Yet thats all where the fluid was , it didn't drip all down my legs or leave the toilet in a bloody mess , just enough to entirely cover my underwear. I thought everything could still be okay as long as I didn't see a clot but in the toilet there was a decent sized clot. * Can attach pic if you guys want* I went to the ER where they told me they can clearly see a fetal pole measuring about 9, closer to 10cm and that there should definitely be a heartbeat at this point but there was not. Idk what to do , i was supposed to have my first ultrasound on Wednesday actually and now this. Could the ER be mistaken? Should I still go to my normal ultrasound and see if they get different results? Im just torn apart right now and anything can be helpful.