According to a column in TownHall.com, the advocates of contraception have finally admitted in public what some of us have known for a while: The Pill doesn’t work very well.  Professor James Trussell of Princeton, one of the world experts on failure rates of various forms of contraception, told a conference in the UK, “(on average) one in 12 women taking the Pill get pregnant each year because they miss so many tablets.” In other words, over 8% of women taking the pill gets pregnant each year. Worse yet, some may be aborting an unrecognized pregnancy and not even knowing it.
My Take?
Most physicians and women that I speak to simply are not aware of the reported failure rates of the Pill.
For example, poor, cohabiting teenagers using the Pill have a failure rate of almost 50% (48.4% to be exact). That means, out of 100 low income girls taking the Pill, who are under the age of 20 and living with their boyfriends, 48 of them will have a pregnancy within 12 months.  
Prof. Trussel said, “Studies have shown women miss three times as many pills as they say they do. Computerized pill packs have revealed that … between 10 per cent and 14 per cent admitted missing more than three pills in a month, actually between 30 per cent and 50 per cent missed that many.”
Also, most physicians and women I speak to do not realize that the birth control pill may have an abortifacient effect. In fact, most are shocked to learn about this possibility. You can learn more about this by reading two articles I’ve written on the topic elsewhere.
For those who are not married, there is no safer or healthier option than abstaining from sex until marriage.
And, for those desiring birth spacing in marriage, there is no safer or healthier option than modern scientific Natural Family Planning. You can read an article I written on the topic here. But, here is some of that information:
Natural Family Planning is a viable option to the Pill Only over the last decade has modern, scientific natural family planning (NFP) become established in the medical literature. Nevertheless, many physicians and most women view natural family planning only as the old fashioned and mostly ineffective rhythm method. The old joke goes something like this: “What do you call a couple who uses the rhythm method for birth control?” The answer, “Parents!” 
Most people (physicians and patients) are simply not aware of modern NFP – much less its many advantages and it remarkable effectiveness. Furthermore, it takes time on the part of the physician and the couple seeking to avoid conception to teach and/or learn NFP. It is much faster and much more convenient just to write a prescription than to introduce, discuss and then teach NFP. In addition, the cost of the Pill is increasingly covered by insurance policies, yet the cost of patient education is not a widely covered service.  
Many are surprised to learn that one form of NFP, developed at Creighton University (The NaPro method), has been medically studied over the last 20 years and has been reported in one meta-analysis to be even more effective than the Pill at preventing pregnancy. Another meta-analysis reported five studies that recorded 1,876 couples who used the NaPro method for a total of 17,130 couple months of use. The method and use effectiveness rates for avoiding pregnancy were 99.5 and 96.8 at the 12th month and 99.5 and 96.4 at the 18th month, respectively. The discontinuation rate was 11.3% at the 12th month and 12.1% at the 18th month.  
The most recent study of this scientific approach to NFP evaluated 701 couples at an urban hospital clinic in the Houston area. After 12 months of use, the following net pregnancy probabilities were found per 100 couples:

• pregnancies related to the method, 0.14 and 
• pregnancies caused by user and/or teacher error, 2.72.
• The authors also reported that pregnancies caused by what they called “achieving-related behavior” (defined as genital contact during the time known to be fertile), 12.84. 

Pregnancy probabilities were similar whether the women had regular or irregular menstrual cycles, had recently discontinued the Pill or were breastfeeding. 
The authors concluded that pregnancy probabilities using this form of NFP compared favorably with those of other methods of family planning and that women did not need to have regular cycles to use the NFP successfully.  
Obviously, in the populations studied, the method is highly effective as a means of avoiding pregnancy in both its method and use effectiveness. The method effectiveness has remained stable over the years of the studies, but the use effectiveness for avoiding pregnancy appears to have improved over the study period.
Another form of NFP, the Billings Ovulation Method, is so simple to teach and use that it is taught around the world, even to people who cannot read or write.  
NFP is said by its advocates to promote love, romance, communication, prayer, spirituality and learning about natural, God-created reproductive mechanisms. Another advantage of NFP is that it is said to foster communication and understanding between the man and the woman, develop cooperation between them and a sharing of the responsibility in this important matter of their children.
In all these ways it is said to improve a couple’s relationship and helping them to grow in love and fidelity to each other.
Since there is a viable, safe, moral, and effective alternative to the Pill, it would seem that couples who believe life begins at conception (fertilization) should consider modern, scientific Natural Family Planning and avoid the Birth Control Pill.
In fact, assuming that NFP is only as effective as the Pill (and not more effective, as it seems to be), it would appear that most arguments to use the Pill, in view of the fact that it may have an abortifacient effect, would be reduced to arguments of convenience at the potential expense of preborn human life.