What Are The Side Effects Of Depo Provera Injection?

i got the depo shot about 7 months ago. i bleed for 4 months and then stopped. yesterday i had to go pee very bad and i looked down and blood there was dark blood all over! and right above my vagina started like stinging with pressure. and every time i've peed now there are black flakes coming out of my pee and my stomach still hurts. what should i do?