Thanks for query,
You have hormonal
imbalance leads to your delayed period.
Hormonal imbalance occurs due to stress
,tension shift duty,night working hours or ovarian lesion.
As you have taken hormones you get withdrawal bleed & then after some time you got other withdrawal of hormones due to irregular supply.
If you will not get it regular then you have to take 28 days pills for 3 continuous cycle to make it regular.