HELP! I have TWO, WEEK long periods every month!

After getting on the amazing, hormone balancing Keto diet and loosing 15 pounds, and after 4 years of no period (due to birth control, or so I thought) I have acquired a period. But not just any period. I get two, REGULAR (almost to the hour) periods (about a week long) each month... like... HUH? I know I should probably go to a doctor, but everything else with my health is the best it’s ever been. Acne, polycystic ovary syndrome symptoms, sex drive, weight, mental health, and many other things are the best it’s ever been in my life. Any clues? Thanks!