Hi, thanks for your question. The protection the birth control pills provide against for pregnancy depends on how you started your pill pack. I have taken the following information from www.optionsforsexualhealth.org where there is excellent information about taking the birth contol pills and other contraception. This is from their fact sheet https://www.optionsforsexualhealth.org/birth-control-pregnancy/birth-control-options/hormonal-methods/combined-hormonal-contrace…
There are three different ways to start taking birth control pills.
1. First Day of Period Start: Start your pills on the first day of your period. Continue to take one pill every day at the same time. With this method, you do not need to use a backup method as the pills are effective in preventing pregnancy right away.
2. Quick Start: Take your first pill today at a good time for you. Continue to take one pill every day at the same time. With this method, you need to use backup pregnancy protection (such as condoms or abstinence) for at least 7 days.
3. Sunday Start: Take your first pill on the first Sunday following the start of your period. If your period starts on a Sunday, start your pill that day. Continue to take one pill every day at the same time. With this method, you need to use backup pregnancy protection (such as condoms or abstinence) for at least 7 days.
If by looking at this, you don’t think you are protected, then Plan B, the emergency contraceptive pills can be taken up to 5 days of the unprotected sex to prevent pregnancy. Hope this helps Health Nurse