Admission chances at Duke University/ACT improvement

Hi!
I’m a junior at a smaller charter school in North Carolina (in the same county as Duke). I have always wanted to go to UNC Chapel Hill (and other less prestigious schools than Duke) because I never thought that I was a very good student, however, in the past year I have discovered that I’m well above average. These are my highschool achievements so far:
Gpa UW: 3.9
AP classes: my school doesn’t offer these until senior year so I will be taking 3 next year
Beta club treasurer
Student government senior representative
Current valedictorian
Volunteer at highly selective Rex Hospital program
4 varsity sports, 1 club sport
Next year I will be taking 4 college classes (community colleges offer this to high school students to get some classes out of the way before college)
ACT composite: 27 (this is obviously very low, however I’m studying over the summer and retaking, hopefully 33+)

Do I have a chance at Duke? And do you think it’s possible that I can bring up my score 6 points?