15 years old; bmi- 16.5, athletic; underweight?!

15 years old; bmi- 16.5, athletic; underweight?

so yeah. im 5'10" and about 115 lbs. my bmi is 16.5, and my doc says im underweight. is this true? i am very athletic (basketball & volleyball, HS Varsity) and i run a lot, but not so that i can lose weight, just so i can be in shape. i was wondering if being athletic like this can lower your bmi? i also dont look underweight, i just look kinda skinny, not in an unhealthy way though..
can i keep up with my training without being worried???

1 week ago
i eat 3 meals a day and i snack in between. i definitely eat enough food in the day and i drink lots of water. im not worried about the way i look, i just want to keep up with my sports

1 week ago
its not like i try to be underweight.. i just am

I'm like you except 4 inches shorter and 15 pounds lighter. My suggestion would be to keep playing the sports that you love and to keep eating lots. Being atheletic and excercising does lower your BMI, but keeps you in shape as well. So as long as you aren't overdoing it keep playing sports and keep eating 3 meals a day with lots of snacks in between.