Norethindrone birth control.

Patient: I am a 16 year old starting the birth control pill Norethindrone. My Doctor said that i would not have a period when i started to take it (which i have not taken it yet) but i decided to read up more about the pill and the articles i have read have said that i would have a period but it could be late or early. What are the real facts? Any information would be useful. And should i start it when my period begins again or dose it matter?