After reading through these posts, I want to share my story in case someone else has the same issues.
Three years ago I quit all processed foods and started running like a crazy person (this was not Whole 30 or Paleo, this was "I wanted to lose weight fast"). I lost 30 pounds but I started bleeding when I ovulated and then two weeks later would bleed again with my period. At the height of my weight loss and activity, I started bleeding everyday. My longest stretch was 33 days in a row.
I was poked, prodded, examined, given the pill, etc.
The end result: I was told that estrogen is stored in fat. If you lose a lot of fat quickly, that estrogen needs to go somewhere and often sparks irregular cycles.
It took about 6 months for things to calm down.
-at the time I was eating a ton of soy products so I know (now) that didn't help either.