Do I stand a chance getting into Carnegie Mellon and Northwestern?

ALWAYS APPLY EARLY DECISION! Especially if they are your dream schools, because you get more aid applying early decision. Secondly, your list is impressive, but your GPA is slightly low for as impressive as it sounds. I hope your AP's increase that, and you mentioned your AP's multiple times...admissions councelors don't honestly care about what AP's you took. Thye care more about GPA and test scores (ACT and SAT), so keep that in mind! But I believe it is definitely worth applying