University Health Service clinicians usually prescribe a "28 day pill pack." The first 21 pills of each pack are your "hormone" or "active" pills. In most brands the last 7 pills of each pack are "blanks" or "inactive" pills, placed in the pack to keep you on a daily pill schedule and you should have a period during this week.
There are three options for starting the first pack of OCPs:
Take one pill every day until you finish the entire pack. Your pills are most effective if you take a pill about the same time each day (within one or two hours of the same time every day).
Your period will occur sometime during that last week of each pill pack. Take all of the "blank/inactive" pills even if your period does not last the entire week. You will always start a new pack of pills on the same day of the week. If you started your first pill pack on Sunday, you will always start a new pack on Sunday. If you started your first pill pack on the first day of your period (e.g. Wednesday) you will always start a new pack on Wednesday.
When you have taken all of the pills in your pack, start the first pill of your new pack. Do not skip any pills, and do not skip any days between packs.
Abstain from intercourse or use an additional method of birth control such as a male condom and/or vaginal spermicide if you have any intercourse during the first seven days of initially starting your hormonal contraceptive method. Hormonal contraception may not fully protect you from pregnancy during this first week of use.
If you forget one hormone pill, take the missed pill as soon as you remember. Take your next pill at the regular time. Taking a pill as much as 12 hours late may decrease your protection against pregnancy. Use a back-up method of contraception for 7 days or abstain from sex for 7 days. If you miss more than one pill, refer to the more detailed information provided in the insert with each pill pack. The risk of pregnancy is greatest if you are late starting a new pack of pills. Use back-up contraception or abstain from sex until you are back on pills for seven consecutive days.
Diarrhea and/or vomiting may occur when first starting your pill regimen. Use an additional method of contraception along with your current hormonal contraceptive method beginning on the first day of any vomiting or diarrhea, and contact the Health Service Phone Information Nurse or your health care provider for additional instructions.
Back-up contraception such as a male condom may also be needed if you are on certain medications such as antibiotics or anti-seizure medications. Consult with your health care provider.
Note: refer to the package insert for problems or questions about use of the birth control pill.