Octal - See also. 1  Computer numbering formats. 2  Octal games, a game numbering system used in combinatorial game theory. 3  Syllabic octal, a specific octal representation of 8-bit syllables.
Your doctor or nurse will suggest 1 of the following methods to begin taking the pill: Start your first pack of pills on the first day of your menstrual period. Use a backup method of birth control (such as condoms with spermicide) until you start the pill.
Take the pill as soon as possible after unprotected sex. The earlier you take the pill, the more effective it is. It should be taken within 72 hours (three days). It is thought to work mainly by preventing or delaying the release of an egg from your ovary, which normally happens each month (ovulation).