What Causes Brown/pink Vaginal Spotting?

Hi, so I have a couple of questions. First off, does brown spotting count as the first day of your period? Or do you have to see blood? Second of all, I am spotting brown and pink right now. My period was supposed to come on the 7th. This started Aug. 29th. I have been spotting every day since. I feel like there is a lot of blood when I wipe, but barely spots on a panty liner. My periods are normally really really heavy with lots of cramps. I have had times before when I spotted for like two days and started my period, but this feels different. I have no cramps and I have been spotting since Sunday night. I've read about implantation bleeding but this seems like I have a little more blood than that. But it's not dark red blood. Mostly brown with a tinge of pink. What is going on? Am I pregnant? Do I need to go to a doctor? help!!