Chances at Caltech

I posted this earlier but it was in the wrong forum so I was hoping you guys could help me out.

Gpa is 5th in my grade, 4.42 (weighted).
My SAT is in the lower part of 50th percentile, 2240 (780 reading, 770 math, 690 writing).

AP tests:
5’s- Biology, Environmental science, Composition, Calc AB, Calc BC
4’s- Physics 1, chemistry, US history

I am doing physics c, economics, literature, computer science, and government all AP this year (econ and lit only because they’re required).

I am also taking a chemistry class with lab at a prestigious liberal arts college and Multivariable calculus at a nearby liberal arts college fall semester. I will still go to the prestigious liberal arts college for chemistry spring semester but I don’t know about math next semester (classes are on-campus, not online).

I didn’t do any subject tests yet, but am doing Molecular Bio, Math 2, and chemistry on November 5. My chemistry professor wrote me a letter of recommendation and I’m doing some projects with him.

Should I try to improve my physics strength by taking the physics subject test in December? And will it hurt me if my chemistry background is really strong but not so much for physics during admissions?
If you guys can help me with any thing else I can do last-minute to prepare for regular decision, I would be grateful.

Do you have any science ECs?

No I don’t have many Extracurricular activities. No competitions won or awards won outside of school.
I see what you mean, though. I should do some more science competitions outside of school.