Pink Discharge

A week ago i was seeing some brown discharge and then 3 days ago i was getting pink thick clumpy discharge. I was getting really nervous because my period was supposed to start Sunday (today) and i had been sexually active a week ago. It turns out it was just my period. Does anyone know why i was seeing this discharge? Was my cycle changing? Im on the pill and its usually pretty normal. I was so scared that some type of implantation had occurred after looking into what pink discharge meant. But my period did eventually come. Thoughts as to what was going on?