How effective is withdrawal as a birth control method to prevent pregnancy?

Like Russian roulette. The penis (gun) is loaded & secreting sperm continuously during intercourse. It only takes one healthy sperm getting trough to get you pregnant. If this is your BC method make plans for pregnancy, since it is likely to happen sooner or later.
Not effective. The man secrets seminal fluid during intercourse that will have some sperms which will render you at risk of pregnancy, this is even before ejaculation. So withdrawal may have been a little bit to late.
Not very. Withdrawal is not very effective for birth control pill. It is essential to use a barrier method if true birth control is required.

Related Questions

Is continuous birth control method a powerful way to prevent pregnancy?

Yes. Birth control pills are an excellent way to prevent pregnancy. They are, however, not 100% and they do not protect you against std's. Taking them in a continuous fashion does not make them more effective.

What is, the next best safe and effective birth control to prevent pregnancy? I don't want any more kids at this time? Should I just keep my iud then

Many options. There are many options for birth control including short term (pills, shots, ring, patch) long acting (IUD, implant) and permanent options (tubal, essure). Visit your obgyn to discuss which options are best for YOU as each one has its risks and benefits.
Yes. IUD's have some of the best success rates, are expensive but give you protection without much effort after insertion. Today's products are also quite safe. If you are comfortable that you never want more kids, a permanent procedure like a tubal (or he gets fixed) is worth considering.

How effective is the birth control pill in preventing pregnancy?

99+% If taken perfectly, - same time, every day, without missing any pills, the effectiveness is quite hi- 99%. However, in practice, the figure is closer to 92% effectiveness, reflecting missed pills, etc.

How long do I have to take birth control for it to be effective to prevent against pregnancy? Does this go for every brand or birth control?

1 cycle. To be on the safe side you should be on birth control pills for 1 cycle before you can count it to prevent pregnancy. Don't forget that it's a good idea to continue using condoms always to prevent std's.

Just started birth control. When will it be effective in preventing pregnancy? And what time frame do I have to the the pills daily? How effective

Within 7 days. You can use your birth control without a back up method within 7 days of starting your contraceptive pills. The best time to take your pill is the time you will be consistent with: if you're a morning person then morning is best, and so on. Good luck!

Is a vasectomy an effective form of birth control? What is the success rate for preventing pregnancy?

Yes. Vasectomy is definitely an effective method of birth control. There are less complications then when a female gets her tubes tied since this is an outpatient procedure. Done correctly and with a test of cure it is close to 100% effective. But you have to be certain you and your wife are done conceiving because it's quite a procedure to reverse it.