What is the most effective pregnancy preventor?

I know that condoms and stuff like that are good protection, but is there like an entirely 100 percent way?

urrrm, the pil a fink lol xxx

Dear cutieπ,
There is nothing but abstinence that is 100% safe. Every birth control method has a percentage of being unsafe. Even the pill is not 100% safe and carries risks.
Sue...good luck

Of course the most effective pregnancy preventer is abstinence (0% failure)

The following are different methods and their failure rates. Perfect use is without human error. Actual use is taking into account human error (forgetting to take pills, antibiotics decreasing effectiveness, using product improperly etc.).

Method Failure Rates
Perfect Use Actual Use
IUD (Mirena) 0.1 % 0.1 % (it's 99.9% effective)
IUD (ParaGard Copper) 0.8 % 0.6 %
Shot (Lunelle) 0.05 % 3 %
Shot (Depo-Provera) 0.3 % 3 %
Nuva Ring 0.3 % 8 %
Ortho Evra Patch 0.3 % 8 %
Oral Contraceptives 0.3 % 8 %
Cervical FemCap 4 % 14 %
Male Condoms 2 % 15 %
Sponge 9% 16%
Diaphragm 6 % 16 %
Female Condoms 5 % 21 %
Spermicides 18 % 29 %
No Method 85 % 85 %

Using more than one method will reduce your failure rate but only by as much as your backup method. For example if you use a male condom and spermicides and the condom breaks, then you're relying on the spermicides which have a failure rate of 29%. But 29% is a lot better chances than if you're just using a condom and it breaks... then there is an 85% chance of pregnancy.

Always have a back up plan in case your birth control fails or if you believe you might not be fully protected. (for example, if you miss a pill... use condoms for the rest of the cycle.) You should also keep a pregnancy planning or gyno clinic number handy in case you need emergency contraception. (if a condom breaks and you're using no other method, you'll need the Morning After Pill ASAP)

Don't forget about STD protection!

More info:
About contraceptives - http://www.contracept.info/risks.php
Birth Control Board on Ivillage(under Women's Sexuality and Lifestyles) - http://www.ivillage.com/health/messageboards
Planned Parenthood - http://www.plannedparenthood.org/

Abstinence is 100 %

The best way is to do a combination of things. For example you could use the condom and the pill.

Your protection is only as good as the strongest method you're using.

Actually, it's as good as the product of the relevant failure rates, as long as the chances of failure are uncorrelated. If you use a condom and the pill, going by sikashimmer's table it'll have a .08*.15=12% failure rate.

The units are also relevant here - I suspect sikashimmer's table is in pregnancies per 100 women per year of use - not per instance!

Actually, it's as good as the product of the relevant failure rates, as long as the chances of failure are uncorrelated. If you use a condom and the pill, going by sikashimmer's table it'll have a .08*.15=12% failure rate.

The units are also relevant here - I suspect sikashimmer's table is in pregnancies per 100 women per year of use - not per instance!

Actually, it's as good as the product of the relevant failure rates, as long as the chances of failure are uncorrelated. If you use a condom and the pill, going by sikashimmer's table it'll have a .08*.15=12% failure rate.

The units are also relevant here - I suspect sikashimmer's table is in pregnancies per 100 women per year of use - not per instance!