Implantation bleeding or just an early period?

I'm not due my period until the 12/3 but I've just started a very light bleed? It's a really light red when I start my period it's normally a really heavy dark red. There's not much blood at all not even enough to fill a tampon. Sorry for tmi just wanted to hear other people's views on this? Also have cramping and sore boobs which I just put down to af coming. Any comments will be much appreciated:).