Recently my brake light started coming on when i would brake during driving, but will stop when its warm outside. which is not a problem just means im going to have to change my brakes i just havent gotten around to it. but my question is why is my brake light coming on when im shifting between gears?

It doesn't necessarily mean the pads are low.

Make sure your fluid is topped off, check the pad thickness [They're supposed to be replaced at 1mm].
If it's neither of these your fluid level switch is probably bad. It's part of the master cylinder cap.

Alright ill check that stuff out. thanks for the help