Breakthrough bleeding, possible implantation ?

Highlighted Orange are my last two days of intercourse, blue are ovulation days, red is me currently bleeding and yellow is what’s supposed to be my regular period week.

I started bleeding a whole week early and it’s light red, and only have used about 2 pads a day. Extremely light. Today it’s been only when I wipe not even spotting on pad. Also only light cramps on day 1 of bleeding. Boobs super tender yesterday (day2) not as tender today only hurts on occasions.

Also not on any type of birth control for over 2 years now.

Any idea of what this could possibly mean?