I had unprotected sex with my girlfriend just one hour before then I went to chemist and he gave me I pill daily contraceptive pills (a pack of 21 small pills) and inside a slip is there in which it is written that my gf has to take it daily 21 days and a table chart shown like she has to take pills starting from 5th day of her periods upto next 21 days daily and after next day periods will come and after 8 days over again she has to take pills daily like something something I get very much confused, previously I thought that I pill should be taken before 24 hours of unprotected sex and only once is enough but I am confused now why tat pack contains 21 pills and why she has to take it daily for 21 days, I wanna know according to my gf situation 1 pill is enough to avoid getting her pregnant or she has to take it daily, what's this mystery I am really confused please help me.