What Causes Spotting And Normal Bleeding During Menstruation?

Hi, well last month I had my period on the 10th. This month it started on the 7th however it was a peanut size of bleed on my tampon for 2 days straight. On the 3th day of my period it was spotting all day, on the 4th day it was a normal period. On the last 3 days it was spotting. Now after that my period ended...until on the 19th I started spotting just a little. My question is ...is that normal or could I be pregnant.