I Been Having Dark Brown Almost Black Thick Discharge For

I been having dark brown almost black thick discharge for a few months straight. It went away for two days then woke up to what looked like I started my period which is normally heavy. I went to the bathroom and a bunch of blood clots and stringy like blot clots come out. Its been two days and its started to become like a discharge but I'm now getting tight stabbing cramps that move to my ribs down to my pelvis