TMI Sorry

So I have very irregular periods and haven't had my period for months I'm not fat or skinny but my doc told me to lose some weight then maybe my period will return on it's own since they ran all the test and everything came back normal. So I'm like f*** it I'm not getting on their birth control or their estrogen pill to try to regulate this thing. So bf and I always have unprotected sex. now my period haven't shown up for almost 5 months and yes I've peed on planty of sticks but all showed negative they even did a blood test to see if I was preggo. So yesterday and all this week we've been having really good sex and my stomach have never cramped up only when I'm having my period. All this morning my stomach have been cramping and I whip I see light blood. is it the start of my period or implantation bleeding and cramping?

that was this morning pic

this is this afternoon pic with still cramping