Thanks for writing in.
Irregular cycles most commonly occur in anovulatory cycles. I would suggest that the first step forward for you to get an ultrasound
of the pelvis done. If this is normal, the next step would be to get a serum FSH, LH and progesterone
level done. Duphaston
would be indicated only if everything else is normal. I would suggest you get the investigations done first. That way we would be able to identify the root cause and prescribe appropriate treatment.
Hope this helps