Irregular periods, hyperpigmentation and facial hair – are these linked?
I’m so happy that you wrote because this is not a rare problem. I’d like to steer you to information and research on something called polycystic ovary disease which can cause a similar constellation of symptoms.
I can’t possibly know if this is the case for you as an individual but this is what I would ask you doctor or gynecologist about and perhaps do some research on the web as well. Just be careful about sources. The major gynecology sites would be a good place to start.
As for treating pigmentation, my guide to understanding pigment problems is a good place to start.
Good luck to you!