28 and still very irregular

Hailey

I’m 28 about to be 29 and have extremely irregular periods since I started at 12. I’ve gone to gynecologists, been on the pill and even then my body still can over ride the pill. I get my period for 3 days then nothing for 3 months then when I get it again it’ll last 7/9 days and nothing for 6 months. Various flows, but nothing else out of the ordinary down there. Is there any specific kinds of tests or things I could ask my gyno to look at ?