Has anyone gone through this or know whats going on?

My name is Andie and im 5-6 weeks pregnant..today i woke up with bleeding and cramping n slight clots so i rushed to the er. They did an ultrasound and the fetus was there and the yok sac was normal but i have an elongated sac and its low but my cervix is firm but there was no heartbeat yet but they couldnt say what was happening cuz its to early to tell but they said it could be a start of a miscarriage. they scheduled me to another u/s so im prayin everything is ok but has ne1 gone through this or know what could happen? im so scared i hope a miracle will happen...