odd brown/pink/tan stringy discharge mid cycle

So it's about two weeks before my period and this week I had weird discharge for about 5 days. It started as a dark brown and was stringy. It turned to a tan/pink. It is now white. Is this just normal ovulation bleeding/spotting or something serious? I've had cramps, sharp pain, headaches, nausea and all the period symptoms along with this. I'm also on the pill. I'm really worried, I'm hoping it isn't implantation bleeding, and it seems to have lasted way longer than that is supposed to last so I don't think it's that anymore.