Spotting?

Bethany
Apparently I'm supposed to start my period tomorrow, the 21st. But this evening I noticed I'm spotting a very light pink color. I thought it was odd since when I normally start my period, I'll start spotting but it's usually a lot darker, like a red. My breasts have also been sore for about a week now, and the pain is getting worse everyday. And they've NEVER been this sore before. Could I be pregnant? My boyfriend and I agreed to wait to take a pregnancy test to see if it's just my period but I wanted a second opinion.