I have been bleeding for 3 days, dark brown, pink, bright pink.

My ob said monitor if it continues go to the ER, went to the ER they told me I am 6 weeks 5 days, heartbeat is good & so are my levels.. but I personally have 8 weeks 6 days. I got a positive 5 days before my missed period. This just doesn’t seem “normal” to be bleeding and measuring 2 weeks early. Unfortunately I see miscarriage happening. Anyone else experience this?