Period or Implantion bleeding

Amie

I started spotting the night before my period. Really it was light pink when I wiped. The next day a light flow started. I put in a small tampon later in the afternoon and didn’t take it out till the next morning. When I did it was real dark, mostly brown, not normal period color for me. Another thing that was different is I’ve had back pain, which I also never have with my normal period. The next day just a little bit of pink when I’d wipe, lots of mucus and the same thing again today. I’ve never had a period like this so now it’s got me wondering if this is implantation bleeding. Has anyone had this happen to them? Please tell me your experiences?