mini pill

hey girls so i take norethridone tablets. progestrin only birth control pills often called the mini pill. has anyone on here taken it or is taking it? do you get your period? when i first started them 6 months ago when i switched from a combo pill my periods became a lottle irregular.. and now this month i havent started yet and i should have started on the 25th according to this app. i am not worried about being pregnant. im just curious as to why i havent gotten a period yet. i have been a little stressed with taking care of my nephew cause hes a bit of a handful. so i was just wondering if this has happend to anyone. or if yall got any advise!