Tanya asked
I'm on a normal birth control pill. My medicine arrived late so I spent an entire week with out my pills. If I start them now will I be protected from pregnancy this month? And if I start them now will it mess up when I get my period? I've been told I can wait until the first day of my next period to start taking them? If I do that when will my pills work to prevent pregnancy?
At a glance
- For most products, if you miss the first week of birth control pills, you should start a new pack (don't just start in the middle of the pack you missed doses on). You should also use back-up contraception for at least 7 days after restarting the pills.
Answer
If you are starting your birth control (oral contraceptive) pills one week late, you may not be protected from pregnancy for about a week if you are sexually active when you start them up again.
In addition, any change in how you take your pills (including missed doses) can certainly affect when you get your period (e.g. it may be early, late or you may miss it entirely). You may also experience "spotting" throughout your cycle.[1]
In terms of when to start your pills again after having missed so much time, you likely will be recommended (by your doctor or per your product's directions) to start a new pack.
Missing Active Pills In Week One
Per the CDC (Centers For Disease Control), oral contraceptive pills need to be used for 7 consecutive days to reliably prevent ovulation, but the riskiest time for any interruption of scheduled doses is just before or after a hormone-free interval.[2]
Therefore, missing doses, especially before ovulation, can increase the risk of pregnancy.
It is recommended, by multiple sources, to consider emergency contraception if you missed any active pills during the first week and you have unprotected sex in the previous five days.
Also, when starting back up, it is generally recommended to use backup contraceptive for 7 days if you are sexually active.[3] This allows time for birth control pills to start working.
Getting Back On Schedule
In terms of starting back up again after missing a week of pills, it's difficult to give you specific information as there are many different birth control products on the market but most recommend just starting fresh with a new pack.
I recommend speaking with your doctor about the best options for you but most sources recommend that if you do miss one full week (over 7 doses), it may be prudent to just start a new pack of pills and be sure to follow any backup or emergency contraception recommendations if needed.
Let's look at one product, Yasmin, for an example. Yasmin is a popular combined hormone contraceptive pill.
If you miss more than 3 pills in any week of Yasmin (and missing the entire first week would fall into this category), it simply recommends starting a new pack and to use back-up contraception. From the prescribing information for Yasmin:[4]
