I think I'd stick to what I believe, especially when I have good feelings about it. Although I would admit that there were many times when I chose to stay silent and let other people's opinions dictate me on what I should do.
However, I realized that not believing in myself won't take me anywhere. If ever what I believe is wrong then I'm ready to face the consequences. It's not as if I'm not open to criticisms. I consider all of these as opportunities to improve myself, and for me to do better next time. I also don't mind failing, for failures get me a step closer to getting it right. Just imagine how boring life would be if there'd be no risks and challenges, and if everyone conforms to a single belief, how then are we going to stimulate new ideas? If we are going to view challenges as how many people view it, then the same challenge becomes true for us. Human minds are capable of thinking unlimited thoughts, so why suppress it? There is nothing wrong in going against the majority and valuing your own opinion because these differences make the world far more interesting.
Point is, there will always be times when you need to choose what you believe in, and have the courage to disagree. Personally, I think I'd rather make a mistake and learn from it, and keep on trying until I'm able to do it right because it is better to regret the things I do than regret the things I didn't do.