I have white spots on my two front teeth that are whiter than the rest of them?!

I have white spots on my two front teeth that are whiter than the rest of them?

When I looked in the mirror a few weeks ago, I saw that there are some white spots on my two front teeth that are whiter than the rest of the two teeth. I use Listerene Whitening Pre-Brush Mouthwash and I brush my teeth twice a day always with Colgate Total Whitening, so why are my two front teeth not consitent in color?

I have a couple white spots too, and I was told they are flouride stains from taking flouride tablets as a child. Maybe you are just noticing them now as the stains on your teeth are being bleached out by your mouth care regimen.