Spotting problem

I'm 19 and I've never had spotting. It's a week before I'm meant to have my period. My problem that's freaking and stressing me out is out of no where my discharge has suddenly gotten some blood in it. It's slowly day by day getting more blood. Looking at my body it looks like where you normally bloat is more 'caved' in which sometimes happens before my period. I have no idea if this is normal or if my freaking out is a good thing. Please help me. (No bad smell or cramps fyi)