Is this implantation bleeding?

sorry if this is graphic. My period is always 28 day cycle and is always regular, my last one started may 2nd. I had intercourse on the 15th and the boy came in me. I did an ovulation calculator and it said i was ovulating right around that time. and now its been about 9 nine days since i was supposedly ovulating and its a week before my period should be here and im having bleeding, Im pretty sure its not my period. and it never comes early. I only bleed when i go to the bathroom. and its a little thick/mucus-y. Its very dark red and almost black. I had very small cramps right when it started but now it just happens and i feel nothing. everything i read online varies and its just confusing so can someone tell me if that really could be plantation bleeding? i also read it should be very little. Its definitely not as much as my period but everyone makes it seem like its literally no blood so i don't know if im bleeding too much or whatnot. im going to take a test in about 3 days but please help!