condom truth

Hi everybody. I see a lot of girls panicking about pregnancy scares and i wanted to make something clear. A lot of you say "pull out worked fine and when i started using condoms it didnt break but i got pregnant". Well, i really would appreciate if you explained how. I want some clarity. Yeah i know each time one has sex there is a possibility of pregnancy but seriously if someone ever got pregnant with condoms, is it really possibile that they used it correctly? Thoughts??