My extra cycle day

I figured out how I was adding an extra day to my cycle numbers. And it's a habit I need to break. You see I want to say I started today on day 29. But since today I started, day 29 doesn't exist, right? Because today isn't day 29, it's day 1. So that would mean my last cycle was 28 days, right? In the end I have a habit of counting my first cycle day twice. So yeah, all my charts have an extra day listed. Oops