In May I Got My Mirena Taken Out And Started

In May I got my mirena taken out and started Sprintec, the pill, right away. I have no idea when my last period was. I am continually taking the active pills, without taking the white inactive pills. I was told that I should eventually take a week of the white pills every 3 months about. If I take the white pills just at a random time for a week, am I still protected from becoming pregnant when I am not taking the active pills.