Hallow dear, I understand your problem.
There are two possibilities.
1. You are pregnant. This seems to be remote possibility since you are on Primolut regularly.
2. The other more likely possibility is the effect of
Primolut N. Primolut is
progesterone preparation. Only progesterone makes the uterine lining thinner and thinner diminishing the bleeding. Thus due to this you could have missed your period.
If it is more than 10 days of missed period, get your urine
pregnancy and/or
ultrasonography done. This will conclude whether you are pregnant or not.
If you are not pregnant, please report to your Gynaecologist. Mostly you will be given Oestrogen preparation for few days to build up the lining of the
uterus and then it will be withdrawn after which you will get withdrawal bleeding.
Henceforth, please switch over to combination birth control pills instead of Progesterone only pills.
I hope this solves your query.