Help...Teeth Whitening is this normal?

I just got a professional tray to whitening my teeth. They showed me how to apply it etc. I have had this problem with weird little white spots on a tooth or two, but over time they have disappeared. HOWEVER, today when I put in the teeth whitening tray for my first 45 min. session the white spots became bright. Additionally, it seems like it did whiten my teeth a little, but the bottom of my front teeth are what seem to be the whitest (which can only be seen if I use a camera) not to the naked eye. This is my first session or first try...Any suggestions? Will these white spots eventually even out with my teeth or go awaY? Ask I continue whitening my teeth with my teeth all become even colored...like the two front teeth will even out? HELP!!