Okay, let me just get this out there. No you don't always have to use a "backup method." that's why there's birth control. Yes there is always a tiny failure rate. There will always be a small chance - no matter what your method is - that you will get pregnant. When someone is first beginning birth control I don't think they want to get "schooled" so to speak by people that think it is required to use a backup form of birth control while on the [pill, patch, shot - whatever.]
don't get me wrong, if you want to use a backup then be my guest. It is safe and obviously will be effective in preventing you from pregnancy no doubt. If you don't want ejaculate inside of you period, then use a condom. I have a boyfriend who was just dying to ejaculate inside of me without the worry of pregnancy. I don't want to be pregnant at this point in my life, so I began birth control. Now we're both happy. End of story. I think I speak for a lot of girls when I say that men like to finish inside of us - I guess it's just something that "does it" for them. Men.. I tell ya. Yeah people get pregnant on birth control everyday. But you have to keep in mind that some of them weren't using their birth control correctly. Some people just aren't careful about it. Then there's some people that use their birth control correctly and still get pregnant. Reason being - that very small failure rate associated with any birth control.
People just beginning birth control don't want to hear "oh well if you're not trying to get pregnant, then you need to use a backup form of birth control all the time no matter what." I know I didn't want to hear that. I wanted to know what every girl wants to know basically. 1] when is it fully effective. 2] am I still protected during my period. You know basic questions like that.
Bottom line: if you're using a valid form of birth control correctly, then you should be protected from pregnancy.
Not lashing out at anyone. Just validating a few things.