period orrr.......??

so here's the run down. gonna try to make this short. I have ALWAYS I mean always had cramps with my periods. and I always know when I'm gonna start because I'll cramp 2.or 3 days before I actually start. my cramps always range from mildly discomfort to excruciating. the past couple years it's closer to excruciating. Well yesterday I had some brown discharge. didnt think.much of it. This.morning I had.some pink.spotting and brown discharge. then tonight it was light bleeding with brown discharge. after my shower it was gone when I wiped. and I've had NO cramps yesterday or today. none. not even a slight abdominal or pelvic pain. I have had unprotected sex this month and glow is saying my next in period is in 6 days? could this be.implantation? I never had that with my first and I don't "feel" like I've had any other early symptoms except I have been sick past couple days with sinus stuff and slight nausea in morning (Which isn't uncommon for me)