Worried about my baby

I am currently 6 weeks and 1 day pregnant and I've been bleeding for the past two days. It started out as spotting and I've read that it's completely normal. But then I started to bleed more and I got scared. Went to the ER and they did an ultrasound, blood work and urine tests. They said the baby was fine. The heartbeat is a little low but they told me it's nothing to be concerned about. They also said the bleeding is normal but the bleeding won't stop and I'm starting to worry about having a miscarriage. Has anyone else had this before and still delivered a healthy baby??