How Effective is Birth Control?

Can you get preggers on birth control? 😳

When it comes to birth control, this is probably the most asked question. The simple answer is, yes (sorry 😬). BUT, the chance of that happening is slim to none. When taken at the same time every day without missing a day, the pill is 99% effective at preventing pregnancy. Where does that remaining 1% chance come from? Read on and we’ll dive into how to reduce the risk of pregnancy on the pill and the factors that might lead to a pregnancy anyways. 

Before we jump in, let’s cover some basics. There are two kinds of birth control pills: the combined pill (which contains both progestin and estrogen) and the progestin only pill. Both pills work using a similar mechanism. 

The main purpose of the pill is to stabilize hormone levels and prevent ovulation, the process used by the ovaries to release an egg. However, sometimes ovulation can still occur, and this is more commonly found in people who use the progestin only pill. The next line of defense is the thickening of the mucus in the uterus. This makes it challenging for sperm to penetrate the uterus and fertilize an egg. The third and final line of defense is the thinning of the uterus’ lining. In the case that an egg is fertilized, the uterus’ thin lining will prevent the fertilized egg from implanting itself into the uterus, forming an embryo, and continuing to grow. 

Now that we’ve covered the basics, let’s explore the reasons behind why a pregnancy might still take place. 

#1: It depends on when you started the pill. 🗓

With the combined pill, you can start taking it on any day of the month. However, when you choose to take the first pill may increase or decrease the chance of pregnancy. If you take the first pill in the pack within the first 5 days of starting your period, you are immediately protected from pregnancy. For example, if you start menstruating on a Wednesday, starting the pill anytime between Wednesday and the next Monday will maintain the effectiveness of the pill. However, if you start taking the pill after Monday, you must continue taking the pill for seven days before you experience the full effectiveness of the pill. Therefore, in these seven days, it’s super important to be using a back up form of contraception, such as a condom, to prevent pregnancy. If you forget, you could get pregnant.. 

Similarly, with the progestin-only pill, you may begin taking it on any day of the month. However, unlike the combined pill, you will be protected from pregnancy after the first 48 hours of starting the pill. Therefore, in the first two days, you should remember to use a secondary method of contraception. 

#2: You miss one or multiple pills. 😬

The purpose of the pill is to stabilize your menstrual hormones in a way that reduces ovulation. Therefore, missing a pill can cause a shift in these hormones that may lead to ovulation. This is especially more prevalent among those who take the progestin only pill. When taking the combined pill, missing one day is less concerning. 

On the combined pill, if you realize you’ve missed a pill, the best course of action is to take the missed pill as soon as you remember -- even if that means taking two pills in one day. If you missed two or more pills, take only the most recently missed pill. Do not take more than two pills on the same day. Complete the remaining course of pills for that cycle. If you choose to have sex during this time, it is important to use backup contraception, as it will take up to seven days for your body to re-adjust to the pills that were missed. You may even consider using emergency contraception (ie. “the morning after pill”) if you have already had unprotected sex. In such cases, you should contact your physician for any further advice. If the pills were missed during week 3 of the pill pack in a 28-day pill pack, it might be recommended that you skip the “placebo” pills and immediately start a new pack.

When it comes to progestin-only pills, the shifts in hormones are more drastic when a pill is missed. Therefore, when you have missed a pill, take one as soon as you have remembered and either don’t have sex or use backup protection (condom) for the next 48 hours. If you have had sex in the previous five days, you might want to  take Plan B.

Another side effect of missed pills is breakthrough bleeding or spotting. Birth control pills are designed to have short term effects on the body’s hormone levels, which is why it is important to take them daily. Missing a pill or more can lead to the effects wearing off resulting in breakthrough bleeding. 

#3: You forget to take it at the same time every day. ⏰

The pill is only 99% effective when it’s used “perfectly”. Researchers have found a difference between “perfect use” and “typical use”.  Perfect use means that you take your pill at the exact same time every day without missing a single day.  “Typical use”, means you may forget to take it at the same time every day or even miss days. Typical use is only 91% effective instead of 99% effective. Taking the pill on time is especially important for those taking the progestin only pill. Even a difference of three hours from the usual time you take your pill can increase your chance of pregnancy.  

#4:You’re taking medication that interferes with the effectiveness of the pill. 💊

Common medications such as antibiotics, anti-seizure medications, anti-fungal medications, and anti-retroviral medications can interrupt the effectiveness of the pill or prevent it from working completely.  Some research has found that antibiotics may increase estrogen levels in the body which directly interferes with birth control pills. 

So, how can you make sure you get the most out of your pill?

  1. If you’re currently using the 21-day pill pack, consider switching to the 28-day pill pack. Sometimes, it can be difficult to get into a routine of taking the pill if you stop using it for 7 days every month. The placebo pills in the 28-day pack can help you with that. 
  2. Regardless of whether you are on the pill or not, consider using back up protection like condoms. Not only does this serve as a second line of defense, but it also helps protect you from sexually transmitted diseases (STDs). 
  3. Create some kind of schedule. For instance, taking the pill right after a certain meal or right before bed can help you instinctively remember to take the pill. Keep in mind that this tip only works if you eat your meals and go to bed around the same time every day. Using the Aavia smart birth control case and app to remind you will make it very hard to forget!   😜

Shameless plug...but our smart birth control pill case is here to solve these problems 🤩 By using our case in combination with our app, you’ll never forget to take a pill on time. Let’s face it. Setting a reminder on the reminder app on our phone doesn’t always cut it. Why? Because we can easily dismiss the reminder if we’re busy. The Aavia app however will consistently remind you until it recognizes that you have removed a pill from the smart case. 

Not only does our app help you to get the most out of your birth control pill, it also helps you record your moods, your symptoms, and have your burning questions answered by our doctors and other community members! 

Download our FREE APP to help you stay consistent with your pill and track your cycle ✌️