Pls help! Any health workers ?

Fatimah • Cooking baby #2 ⏳
I was 16days late for my second period after giving birth.
And finally when I got my period
It's not stopping im on day 8
I normally last 5days.
I thought it was a miscarriage 
Since I was having all the pregnancy symptoms. And I took a test today 
(Still bleeding) it came back negative.
I was hoping hcg levels can still show.
But nothing.
My bleeding started with light bright red bleeding to heavy bleeding with large blood cots that I've never experienced. And now I feel super weak and cramping.
Still bleeding I have to change my pad at least twice in a hour