Implantation or early period?

So according to Glow, I have a 32 day cycle and I'm on day 30 so my next period should come in 3days. Well I had unprotected sex on the 16th. A couple days after my fertile window ended. And this morning I experienced light cramps(partially due to constipation, sorry if tmi) but during these light cramps I felt cramps generally in my lower right side. All morning I've gotten pinkish brown colored milky white discharge only when I wipe. So my question is could I just be getting my period early? Or could this be inplantation?