what brand is it?

if you miss one active pill do not start taking it early just miss a day. you probably dont need to use a backup form but if you want to just to be safe you can. it also depends on how long you have been on it. if you have been on it for years its probably not that big of a deal. the thing id be worried about is that it might mess with your period when you start in a few days. why dont you just call your doctor/obgyn and ask? every pill is different. i take nortrel and if i miss a day im fine but im also on it for PCOS so my doses are a little different than most pills.

or you could just not have sex til you start your new pack?