you can use them but your better of using them in conjunction with other mthods as well, like opks :)
I tried that when I got pregnant the first time but I took my last test today but the calendar said I am suppose to ovulate tomorrow just want to see did anyone get pregnant by using the calendar....
I used an application on my phone to track periods, sex, and ovulation. When it said I was ovulating, I initiated the deed, which is rare in my marriage. Currently 26 weeks with a pretty little girl.