Did I just start my period?

eddie

My period is apparently supposed to start today, but as far as I'm aware it hasn't happened yet. However yesterday and today I've noticed a sort of reddish brown tint to my discharge?? It's not like spots of blood or anything, and it's hardly noticeable, but it left a bit of a stain on my underwear...is this thr beginning of my period?? Or something else?? I've never had this happen before, please help!!