A 16-year-old female is referred to your clinic with a chief complaint of primary amenorrhea. She denies ever having spotting or cyclical abdominal pain. She reports the development of breasts 2 years ago, pubic hair 1 year ago, and an increase in height over the last several months. There is no reported history of excessive weight loss or gain. The patient endorses an increase in vaginal discharge in the last year. The patient states that she is physically active and participates in sports year-round. She reports eating a healthy diet including all food groups. She denies any body image issues. She denies sexual activity. Her father states that the patient has tracked along the lowest percentile for weight and height on the growth chart since early childhood.