Periods on Mini Pill

Marie
I'm on my second pack of Norethindrone Progestin-Only Mini Pills and I have not had my period yet. It's driving me absolutely insane. My projected period start date was either three days ago or today (I use too different apps and got a new phone). I really don't want to worry but I can't help it. 
Has anyone else experienced this and what should I do (or don't do)?