White spots on my teeth... Orthodontist said its normal??

Lately I noticed that small white spots on some of my teeth,I wear braces btw, I was worried that my teeth could have been decaying or somth like that but when I went to see the orthodontist he said its not decaying and the white spots are normal??? I don't know whether to trust him or not, I've done some research about it on the Internet and it all states that white dots are a definite sign of tooth decay, I'm really confused and I don't know who to believe, what do you guys think?

Hi, I kinda have a white/yellowish spot which is not small on one of my incisors. My dentist told me that it is caused because I some how had an infection whilst my adult tooth was growing :/. Also braces is one of the other causes.

Mine are small, but my orthodontist never gave an explanation on why it is caused, he only told me not to worry and that my teeth is not decaying... If that's not the case then why would white spots appear... Maybe I should ask my dentist instead. Do you still have braces on, if so how is it going?