Period or Implantation

Hi beautiful! 

So, I started spotting a day before my period was actually due. The next day I had blood like a period but not a heavy one and then the next day after that it was light bleeding. Well now I'm having two days of brown spotting. My period last six days and I have never done this before. 

Any idea of what this could be? Has any one had this and they ended up pregnant or just a period? Something serious? TIA