3 weeks pp and heavy bleeding with sharp cramps

Hannah • Hey my name is Hannah. I am a 27 yo SAHM 💙👶🏻 💙4/29/16 💙👶🏻 💙4/23/18
I gave birth three weeks ago. I have had a steady flow of red blood consistently. It's enough to fill up a pas every one and a half to two hours  I called my doctor and they told me it was just my period and to stop worrying. Well today I passed a few clots and have been getting really sharp intense cramps in my uterus. I had a bad delivery where my placenta was fused to my uterus and I lost 1500ml of blood and during my pregnancy I had a SCH and nearly bled to death several times. So I am a little worried about this. Has anyone had a similar experience they can share to reassure me it's normal?