TMI‼️⁉️

I have no idea what’s going on, I’ve never had anything like this happen. For the last 4-5 days I’ve been cramping really bad and having this black goo type discharge. It doesn’t have a smell at all it’s just this discharge. I also have some red blood when I wipe but mostly I just get this black goo. I haven’t had a period since January because I got on the depo birth control shot. Does anybody have any idea what this could be? I called my gyno but he can’t see me for another week I’m really concerned. Has anybody else experienced this? Anything will help.