So I'm on week 3 of the pills and this is my first pack. I'm mainly taking them because my flow is too heavy, and beyond painful. With the pills, will the last set (week 4) of inactive pills CAUSE my period to start even if I'm generally on a 38 (not 28) day cycle? I'm super confused, and the pamphlet explained nothing, and since I'm in a super conservative state we aren't taught about birth control at all (I didn't even know I could get it at 17). Someone please explain this to me, I'm super confused. I take the pill everyday at 12 (though in the last week I missed it and took it about 4 3 times).