Period blood was green now is black!

Amber

So yesterday my period blood was a greenish brown type of color but was more on the green side. Now I went to the bathroom and my period blood was black on my pantie liner. What does it mean! I have also been bleeding for 43 days and so I don’t know if it is the end of my period or what. I have also already been to the doctors and a gynecologist for how long I’ve been bleeding and they said it was a long time to bleed but that they can’t do anything until November when I’m suppose to get my new depo shot