Implantation bleeding help

Molly
Hey ladies, I need some help, I am patiently waiting for a BFP after a misscarriage in April and hoping this month is it. I am due for my period tomorrow (friday) and I have been experiencing some brown/light pink discharge when I wipe since Tuesday. I was hoping it was implantation bleeding but not sure?  I have been taking pregnancy test since Wednesday but all negative. I feel
Similar to the way I do when I found out I was pregnant before but also know that it could just be PMS. What do you all think, implantation bleeding or just breakthrough bleeding before my period is due? Has anyone experienced anything similar? What were your symptoms? Thank you!