Is there any safety period of my wife while making with her will not make her pregnant?

I'm gonna marrying soon, by the will of my creator. I do not want to use condoms because these may hamper my satisfaction. Neither do I want to allow my wife to take contraceptive pills because this may also cause harm to her health. I heard that there is a period comprising 10 days before or after the menstruation during which making will not make my wife pregnant. How much true is this? What is that safety period exactly?