Heavy implantation bleeding?

My period isnt supposed to start for another week and it always very regular. Last night I started bleeding (I'm 7 DPO). I normally have extremely heavy periods, going through a tampon every other hour. Currently my bleeding is lighter than a period usually starts but seems too heavy for implantation from what I've read. I've also had unprotected sex all month, and every other day during my ovulation week.

Does this seem like my period is starting early, implantation bleeding, or something else entirely?

I don't know if because I have such heavy periods, if that would make my implantation bleeding heavier.