How do i know if i have depression?

doesnt every teenager get depressed and go through that stage. Should i actually do something about it or let it p? Im not sure if im depressed or just stressed but i think maybe i just let things get to me because im sensitive. im not sure. i dont really want to call a hotline because i always feel awkward and i dont want to go to a school counselor because crap gets around the school like that. And i heard it made it worse for a person who went because of the fact that people knew. and i dont want people judging me just because i went to our counselor.