Implantation or af...

So ladies, I'm currently around 10dpo and I've had tender boobs for the past 2 or 3 days and felt tired and quite warm, I'm not due af for at least around 3 to 5 days yet, I have had no cramping or anything, felt more hungry than normal and had massive headaches for a few days either this week to the point where it was migraine worthy, anyway I went to the toilet about 10 minutes ago and I had a spotting incident, it was more like a light brownish colour but I've still not got any period symptoms at all like I normally do, please help, my hcg test was negative this morning so is it possible I may have tested too early? ....