1. As the person above me mentioned, the pill is just under 100% effective by itself, about 98% or so I believe.
2. Yes and no. Women are not usually fertile at that time if (that's a big if) they have the perfect 28 day cycle with ovulation occurring about day 14. Not many women have that perfect and predictable cycle, however. That is why birth control is needed every time. Women can even get pregnant when they are having their period! Sperm can live a little while in the vagina, and also we just don't know exactly when we are going to ovulate.