Implantation or period??

I have a few different kind of apps here on my phone and all of them tell me I'm suppose to start on different days I have been going off glow since this is the one I mainly use and put in the most info here...I'm not suppose to start for another 5days and I went to the bathroom earlier and had a very small amount of blood I have been a little crampy and somewhat bloated. On one of my other apps it said I was suppose to start today so could this be the start of AF or something els?!?