Causes of an irregular cycle?

Ashton
I've had irregular cycles since stopping BC 9 months ago. I've had some come 4-6 days early and then some come 15 days late. I will have my progesterone levels tested on June 30th and possibly start Clomid. My exam and pap were good/normal. What else could be causing this? OB said it likely isn't the BC this long after stopping. Thanks