Thanks for query,
What is your age?
Mirena is not causing ovulation to cease when it is in place and the amenorrhea
(lack of periods) many women using Mirena experience is due to the very thin endometrial lining caused by Mirena in most women.
Mirena can cause disturbed periods but it cannot postpone the cycle permenant.
You have hormonal
imbalance causes this condition.
Hormonal imbalance can occur due to Tension,Anxiety
,Delayed hours of working,shift duty,any pathological lesion of ovary,menopause
You must consult your doctor to diagnose it.