Sorry for the tmi, but I've been bleeding for about 3 days, and having bad cramps off and on. I'm on…

Sorry for the tmi, but I've been bleeding for about 3 days, and having bad cramps off and on. I'm on the depo shot, and haven't had a period or bled in a few months, if it was just dark blood and extremely mild spotting, but I'm now having to wear a pad and it's bright red/pink blood. Has anyone else had this randomly?