Hi Sam.
Yellow discharge indicates an infection of some sort. Now that you're being sexually active with a partner, you need to become familiar with your sexual health. It's time to visit your local women's clinic or Planned Parenthood. They have low-cost or free services for teens and can prescribe a medication that will clear up your infection. Call now. This won't go away on its own and could be quite serious. Best of luck to you. Dr. J
you probably got yeast infection from your boyfriend. you need to visit gyno doctor