It is very difficult to comment on your query as your period was due on 23rd of June and you did not get it then.
You have started taking Primolut N
from July 1 st onwards. But, there are fair amount of chances that you could have been pregnant on July 1st itself.
I mean to say that even before you started taking Primolut N, you could have got pregnant.
I am unsure if the drug is really going to help you in preventing pregnancy
If you do not get your periods within 7 days of stopping Primolut N, please do a home pregnancy test. Consult your General Physician accordingly.
Happy vacation and enjoy your trip.