When to expect period. My periods?

I went to a gynaecologist about having missed my periods in the month of November. Only spotting happened for 4 days but with a gap in the middle. So it was like 2 days spotting, 3rd day nothing and 4th and 5th day spotting. I did not have unprotected sex from the last cycle which ended around 4-5th November. And this spotting happened from 26th November. Although I did have unprotected sex on 28th but no ejaculation was done inside. My doctor asked me to take a pregnancy test on the 5th or December and told me if it was negative, I take Estrogen and progestin pills from that day itself and that I'd have my periods around 15th. It's the 16th today and I still haven't gotten my periods. I did a pregnancy test again on 12th and that was negative too. But I don't know when to expect my periods now. I can't even get a clear picture of what these hormones do to my body and when to have the periods. Can someone tell me when I could expect my periods?