Primolut N and periods. Am i pregnant?

I had started taking Primolut N on 22nd May and continued till 25th May two tablets a day after having unprotected sex on 7th day of my periods and took no contraception. And I got no periods till now. But I feel like I will get periods as my back and stomach ache lightly sometimes. I am experiencing this light pain once everyday after I have stopped medication. Is this the side effects of the medicine or should I be worried about this situation now? My doctor asked me not to stress out and wait for the periods till 1st June. But it is 2nd June today and I didn't get periods yet. Am I pregnant? What could be the other reasons of not having periods till now. My menstruation is regular and my last date of periods was 29th April. Kindly help.