What should you do if you were going to skip your period and you took the first pill of a new pack but then changed your mind?

There is no harm in this whatsoever. So you took 22 active pills in a row. Now you can take seven (or six, or five, etc.) placebo pills, have a withdrawal bleed, and then start your new pack. There is no increased risk of pregnancy from taking 22 active pills instead of 21. Just remember to never go more than seven days without an active pill.