Is It True You Need To Wait One Week After Starting Birth Control Pills To Be Protected From Pregnancy?

In our latest question and answer, our pharmacist discusses how soon you are protected from pregnancy after starting birth control pills.


I recently started taking the contraceptive pill, and was told that you need to take it for a week before having unprotected sex. I started the pill on Wednesday 5/03/23 and had unprotected sex yesterday (Wednesday 5/10/23). Although it has been a week since I started the pill, I didn't take the 7th dose until after I had sex yesterday. So, in reality, I had only taken the pill for 6 days before having sex. Is there still a high risk of me being pregnant?

Asked by Micky On May 11, 2023

Answered by
Medical Content Reviewed By HelloPharmacist Staff

Published May 12, 2023
Last updated Apr 02, 2024

Key points

  • There are two ways to start birth control pills: 'Sunday Start' & 'Day One' start.
  • Protection from pregnancy depends on the method. The 'Sunday Start' does not offer immediate protection from pregnancy while 'Day One' start provides immediate protection if started on the first day of your period (i.e., the first day of menses).
  • If you started taking your birth control pill on a day other than first day of period, wait for 7 consecutive days of pill administration before considering it effective as a contraceptive. Back-up methods are recommended until reaching the 7-day mark.


The answer to the question of whether or not you need to wait one week before having unprotected sex after starting birth control pills for the first time (in regard to being protected from pregnancy) depends entirely on which day you started your pills.

There are two different ways to start taking oral birth control pills:

  • Sunday Start
  • Day One Start

If you are a 'Sunday Starter', you are not immediately protected against pregnancy and you should wait one week after starting to consider the pill an effective contraceptive.

If you are a 'Day One Starter', you are immediately protected against pregnancy if you start taking the pill on the first day of your period. 

Difference Between The Methods

Sunday Start Method: This method involves starting the pill on the first Sunday following the start of your period.

For example, if your period started on a Wednesday, you would wait until the following Sunday to start taking the pill.

The Sunday start method is convenient for many women because it allows them to associate taking the pill with a specific day of the week. However, it does require waiting until the first Sunday following the start of your period to begin taking the pill, which can be inconvenient if your period does not align with the Sunday start.

Additionally, if the first day of your period is not Sunday, you do not have immediate protection against pregnancy.

Day One Start Method: The Day One start method involves starting the pill on the first day of your period.

The Day One start method is convenient for women whose period does not align with the Sunday start. It also provides immediate protection against pregnancy if started on the first day of the menstrual cycle. However, it may be difficult to remember the exact day of the month to start taking the pill with this method.

Additional Information

You stated in your question you started your birth control pills on Wednesday.

If that was the first day of your period (which would be considered a day one start), you are immediately protected from pregnancy.

However, if that was not the first day of your period, the general recommendation is that your birth control pills should not be considered effective as a contraceptive until after the first 7 consecutive days of product administration.

I don't know which group you fall into here...If Wednesday was not the first day of your period, having only taken 6 consecutive days of pills, you technically would be considered at a higher risk of pregnancy, although that risk would still be quite low. Regardless, back-up methods would be recommended until you reach that 7 day mark.

Final Words

I hope you found this helpful! Please contact us again anytime.


  • Yasmin Prescribing Information, AccessFDA
  • Contraception Update: Oral Contraception, PubMed

About the Pharmacist

Dr. Brian Staiger, PharmD

Dr. Brian has been practicing pharmacy for over 13 years and has wide-ranging experiences in many different areas of the profession. From retail, clinical, program development, and administrative responsibilities, he's your knowledgeable and go-to source for all your pharmacy and medication-related questions! Dr. Brian Staiger also has herbalist training and educational certificates in the field of medical ethnobotany. Feel free to send him an email at [email protected]! You can also connect with Dr. Brian Staiger on LinkedIn.

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