Before I chance, there is more information needed:
What APs did you take, and what scores for each?
What is your senior course load? Course rigor matters for Duke and these other schools.
Even if your school does not rank officially, many schools provide a profile to colleges that will somewhat stratify GPAs–are you in the top 10%?
Would your teachers likely describe you in your recs as one of the top few kids in the grade? The best this year? One of the best in many years?
Is it a regular public school or a magnet/test-in school? Did you take the SAT but are not submitting it?