To be frank- the pull out method is horrible in my opinion.
First- the success rate of that method (as in the ability to actually avoid conception) is VERY bad- pre-ejaculate can impregnate you (I know many a woman with babies as proof of that!)
Second- it is a mood killer. I won't go further then that because the specifics of sex really don't need to be discussed.
All that said- NFP, rhythm and calendar methods of birth control are three VERY different methods. NFP or "fertility awareness" is a great deal of work for the wife. If you want to know more about it read "Take charge of your fertility." My husband and I have used this method for about 10 years and we have 4 children ages 8, almost 5, almost 3 and almost 1. You can ovulate twice in a cycle, my two youngest are proof of that
Calendar/rhythm is mostly about counting and since most women don't adhere to the "average" cycle where you ovulate on day "x" the failure rate of this type of pregnancy avoidance is higher then NFP/fertility awareness.
If you combine fertility awareness with a barrier method during fertile periods then you don't have to avoid very often. Otherwise there would likely be at least 2 weeks out of the month when you would have to avoid since the menstrual cycle is around a week and you have to avoid for a few days as your fertile signals start to ramp, while you are fertile and for a few days after. Women tend to have an increase in libido during fertile periods, so avoiding during that time can be (for some) a very difficult thing to do. And with fertility signals sometimes being a "gray" area (if you read the book you would understand more what I mean. There are "fertile" signs, "possibly getting fertile" kind of signs and "not fertile" signs that a woman's body gives.)
Gebre- you speak like men are the only ones that want to have sex! That isn't the case!
When you avoid during fertile periods you are depriving BOTH people.