Dear Ashley,
Many women have one breast that is smaller than the other. It's well within the range of normal. In puberty, you are still developing, and they may get more even. A little bit of tingling is not a cause for worry. Tingling and tenderness may be especially common right before a menstrual period. If you develop real pain that lasts longer than a menstrual cycle, you would want to call that to the attention of an adult who can get you a medical appointment.