What Causes Delays In Menstruation?

Dear doctor the two last week of last december befor my period in 5 days i took primolut nor to delay my period i took 2 pills tdaily for 16 days and then i stoped it after 2 days i got it and now its been 5 weeks after my period i still didnt get my period im one week late from when i got it last time is taking the medication for 16 days affecting that im late should i take primolut nor aggain now as well i want to get my period since next weekend im travelling so is there something i can take so i can get it straight away