I'm 19 years old and my teeth are yellowing. i do not smoke or drink coffee. i recently have been using hydro peroxide then brushing teeth. any advice?

Start + See Dentist: 1) use a soft manual toothbrush. 2) place the brush where the teeth and the gum join together. 3) move the brush in circles. 4) do all teeth this way on the face side and the tongue side. 5) initially the gum may bleed because you are cleaning out an open sore, however this bleeding will stop and the tissue will now begin to heal. 6) follow up with a water pik spraying water in circles same places.

Bleaching: Sounds like bleaching may be best. You can consider otc options but options through a dentist will be more effective.

Overdue: Sounds like your very overdue for a dental examination and professional cleaning to remove surface stain and accretions. Your dentist can then work with you to whiten your teeth. This isn't a diy project. You need the help of a pro.