Implanation bleeding or just a early period ?

Ok so i had unprotected sex before and on and after ovulation, 3 days later i had lower abdomin cramps and then back pain. ive been taking naps and my temp is at 98.7 and yesterday i noticed when i wiped there was some medium colored pink on the TP and it was very light not even enough to go in my panties. then it went away for a few hours, then i wake up this morning, and there was a more dark red when i wiped still not enough to be in my panties... my period is not due till the 15th could this be implantation blood or a very light period that is early. i never get pain when i have my period and this past 2 weeks i have had a lot of pain in my lower back and abdomin.

please someone help with this. cuz my period is normaly very heavy but this is nothing like that. i never get pain i never get tired and i never have mood swings but now i snap at every little thing my BF says.