When I was younger, I didn't brush my teeth regularly, and my parents didn't notice/care. So now my teeth are yellow. I brush them twice a day for 3 minutes each time, use mouth wash and floss everyday. I've also tried whitening strips, But my teeth are still not turning white. Is there any effictive ways to make them white?

Yes, professional whitening procedures.

Contact a Dentist in your area.

Contact your dentist and make an appiontment. The dentist blech your teeth. Or you can use baking powder because it always help me.