implantation bleeding?

Abbi
So my period has been messed up lately. A few months ago I missed a whole month and thought I was pregnant but got a negative. Ever since it's started a week later. I had unprotected sex on my highest ovulation day a few weeks ago and now my period is 6 days EARLY! It has never been early before!!! The blood is more pinky red and a lot more than what I normally get (a tiny bit of brown blood is normally the start of my period). Obviously if I miss my period I'll get a test. Could it be implantation bleeding?