implantation bleeding or period?

My last period was Nov 14 next period is Dec 12
I had sex during ovulation Nov 29th being one of the days where I had clear stretchy egg white cm (I was at my most fertile).
Today, Dec 6 I wake up and go to the bathroom to find blood in the toilet. Keep in mind that the night prior (Dec 5) I had very slight cramps in my lower back. Even the day before. Not period cramps bc they weren't as harsh and painful. This is also a week after I had sex AND exactly a week before my next period. BUT later on that day it got a little heavier.. not heavy enough to need a pad or tampon but it definitely wasn't spotting anymore...
So I guess my question is... is this implantation bleeding or my period? Because this is the exact day that IF I were pregnant I would be having implantation bleeding. So what the hell is going on!???!???!