Is bleeding normal?

I’m currently pregnant with my first child and I’m measuring around 4-5 weeks. Ever since the day I found out that I was pregnant, I have been bleeding. At first, the bleeding was very heavy, so much that I had to go to the ER for a possible miscarriage. They had found some pregnancy tissue in my ultrasound and advised me to go see my doctor at the women’s clinic for a possible ectopic pregnancy since my HCG was at a 12.

From then on, the bleeding began to let up. It became no more than like a light-medium period. However it hasn’t stopped since. Usually the flow is dark like old blood that’s mixed in with red blood. I wasn’t too concerned about it since I thought it was implantation bleeding, however it has been going on for about a week. Should I be worried or is this a normal thing to experience?