✔ 最佳答案
The Pill acts by preventing ovulation and also by over-stimulating the uterus to offset implatation of any fertised egg.At the end of taking the 21 active pills,you will not have an ovulated egg getting into the uterus to get fertilised while the uterus is also not prepared for any egg , fertilised or not,for further development.
Therefore,the most important thing about taking contraceptive pills for contraception is "Don't miss out any pills" as directed by the manufacturers.
The difference between the 21-pill and the 28-pill packs are the extra 7 dummy/placebo pills in the 28-pill pack often of different size and shape.
If you had taken the 21 active pills,except for the very first and sometimes second packet,whence additional use of other contraceptive methods like condom, are also highly desirable,then you should be almost 200% safe from getting pregnant.
So,you are not likely to get pregnant during the 7-day period after taking the 21 active Pills.
The drug companies warn that there is a 3-5% failure in preventing pregnancy while on the Pills ;this includes those who do not take their pills as specifically directed.
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2007-02-11 13:13:25 補充:
Correction: "Don't miss out any pills" should read "Don't miss out any pills".
2007-02-11 13:16:20 補充:
Correction again:Correction: "Don't miss out any pills" should read "Don't miss out any pills". 'should read as {Do not miss out any pills].