Vegan + PCOS

I’ve been vegan for almost a month (since the beginning of April)

Having PCOS I understand having irregular periods is something to expect but my period has been on the same day, for the same amount of days, with the same flow + symptoms for almost 4 or 5 months now since being on birth control.

Here’s the issue: since going vegan, Aprils period has been 12 days & prolonged into the month of May, no symptoms, a lighter flow.

When should I talk to a doctor about this 12 day period? Is this normal?