What is a healty weight?

I'm 17, 5 foot, 5.5 inches, and weigh about 106 pounds. I know my BMI says i'm underweight, but i'm DEFINITELY not one of those people who skimps on meals (i usually eat more than my boyfriend does haha) Though i don't eat any junkfood-lots of fruits and veggies :) so would you say that is underweight, or healthy?