Miscarriage?

I am 6 weeks along and this morning I woke up with spotting so I went to the ER and they gave me an ultrasound and confirmed a heartbeat?! Great right? Well on my way home I started heavily bleeding. When I got home I passed 2 big blood clots and have been bleeding and cramping for the past 4 hours.

The doctor had just told me that once they hear the heartbeat the chances of a miscarriage go down to 2%. I’m so confused. Has anyone had this and still ended up having a healthy pregnancy?