Does anyone know how long after you start taking birth control does it start being affective?

I've been on birth control for about 3 months...a low dose..just wondering if we should also be using condoms..how long does it take after you start them for them to be completely affective??? I know they do not prevent 100% but how long does it typically take for them to get into your system enough to prevent pregnancy??? Thanks!Does anyone know how long after you start taking birth control does it start being affective?
From what I remember it takes about 2 months to get into your system and 2 to get out. Remember this is not a full proof protection and unless you are ready to take on the responsiblity of a child I would use a condom also. You can try using a female condom to make things better. Deffinatly look into it.Does anyone know how long after you start taking birth control does it start being affective?
At least one full cycle but many doctors will tell you to use another form of protection for 3 months.... if you've been on them for 3 months you're as protected as yo'ure ever going to be now.
all my life I was told 1 month. so i would go with that. and the pill is not 100% effective, so use the condom as well.