Implantation bleeding

I have been having brown spotting since Friday afternoon. It was heaviest when it started and had gradually decreased. Now it is not every time I wipe like it was when it started. How long did your implantation bleed last when you had it? I did not bleed with my first two girls so I am a bit concerned 😳. I am just assuming it is implantation at this point. I had a miscarriage in January so I am a little on edge about it (I never had any bleeding with that one either)