I Had My Period On Jan 6th, 2016 Through To

I had my period on Jan 6th, 2016 through to the 12th while I was on Sprintec birth control pills. I was getting migraines so I had my doctor switch me to norethindrone mini pills. She did not tell me whether or not I would get a period while taking these pills. However, right when I started the mini pills I got a period from the 19th-22nd. I did not even think to ask about the sugar pills and if i should be getting a period because I was so used to the sugar pills with the sprintec that I did not know there isn't a different color for the sugar pills in a mini pill.. so my question is, am i supposed to get a period while taking norethindrone? I have had intercourse without a condom a couple times since starting the new pill and havn't been taking it as i should. I took a pregnancy test today around 12:30pm and got a negative. Was it too early to take a pregnancy test? I am not sure if i tested too early or if i should even be worried about testing at all. Thank you for your time.