The morning-after pill & ovulation
Julie Medical Advisor
If you’re considering taking the morning-after pill, there might be a lot of questions running through your mind like: Will it work for me? To answer that, we first have to talk about timing. You want to take the morning-after pill, like Julie, as soon as possible because the sooner you take it, the better it will work. Studies have shown that the morning-after pill is 89% effective when taken within 3 days of unprotected sex and potentially even more effective if taken sooner. In addition to timing, effectiveness also depends on where you are in your cycle, like if you’ve ovulated or not.
Here we’ll cover everything you need to know about how Julie's effectiveness can shift depending on where you are in your cycle.
Will the morning-after pill work during ovulation?
Julie, Plan B, and other OTC morning-after pills are highly effective at preventing pregnancy by delaying ovulation. As a refresher, ovulation is when the ovary releases a mature egg, which happens sometime between two periods. The egg moves down the fallopian tube over the course of 12-24 hours, which is when sperm could potentially fertilize it.
Since the morning-after pill stops ovulation, the ovary doesn’t release an egg. When there’s no egg, there can be no fertilization and thus no pregnancy. This is why Julie and other morning-after pills are so effective when taken at the right time.
Now you might be wondering: does the morning-after pill work after ovulation has already happened? If you’ve already ovulated and took the morning-after pill, the pill may not be as effective in preventing pregnancy. However, depending on where you are in your cycle (and a number of other factors) that doesn’t mean you’re automatically pregnant.
If you're unsure whether you've already ovulated or not, there’s no harm in taking Julie. It might work for you, and if it doesn’t, it can’t harm you or a fertilized egg.
How successful is the morning-after pill during ovulation?
Levonorgestrel, the hormone in all OTC morning-after pills, prevents ovulation if taken in the pre-ovulatory period, aka before you’ve ovulated. Levonorgestrel works by blocking the luteinizing hormone (LH) surge, which is when the ovary releases an egg. If levonorgestrel is taken on the day of the LH surge or later, the egg will have already been released, which means it can be fertilized by a sperm. If the egg has been fertilized, there is a chance that it will implant on the uterine lining and turn into a pregnancy.
Basically, if your egg has already been released (ovulation), then the morning-after pill may not work, but that doesn’t automatically mean that you’re pregnant. In fact, one-third to one-half of all fertilized eggs never implant on the uterine lining, meaning they never turn into a pregnancy. Not sure if you’ve ovulated? Here’s how to tell.
Does the morning-after pill work after ovulation?
Morning-after pills, like Julie, prevent pregnancy by stopping ovulation. They have no effect during or after ovulation. If you've ovulated in the last 24 hours, the morning-after pill will have no effect. If it’s been over 24 hours since you ovulated, the morning-after pill will not be effective, but your chance of getting pregnant is lower.
The only type of emergency contraception effective during or after ovulation is the copper intrauterine device (IUD), which must be inserted by a healthcare professional within 5 days after unprotected sex. Copper repels sperm and prevents it from fertilizing the egg.
The best way to prevent pregnancy throughout your cycle is to use a regular form of birth control, including:
- Daily birth control pill
- Vaginal ring
Understanding your menstrual cycle—and when you're most likely to ovulate—can help you know if taking Julie will be effective after unprotected sex.
What is ovulation?
Ovulation is part of your menstrual cycle. A new menstrual cycle begins on the first day of your period. After your period, your hormones tell your ovaries to prep another egg. Ovulation is the phase in which a mature egg is released from the ovary.
Two things might occur after the egg is released:
- Fertilization: when the egg is released, it may be fertilized by a sperm if sperm is present in the fallopian tube. If the egg is fertilized and implants on your uterine lining, then a pregnancy will begin.
- Non-fertilization: after release, the egg will survive for 12-24 hours. If the egg isn't fertilized by a sperm, it will dissolve. After that, the uterine lining will shed during your period.
Ovulation takes place in between your periods. For instance, if you have a 28-day cycle, ovulation would occur around or on day 14. But every woman's cycle is different, and the exact day of ovulation can differ from month to month and person to person.
How do you know when you're ovulating?
While ovulation occurs monthly, it's not easy to predict. Even if you track your menstrual cycle, ovulation can be delayed by external factors like stress, diet changes, or even changing time zones.
Here are three ways to know if you're ovulating:
Track your cycle
If your period happens every 28 to 30 days, ovulation normally occurs on day 14 or 15 if you're counting from the first day of your period. If you're feeling ovulation symptoms (listed below), then there's a good chance you're ovulating.
Vaginal discharge often changes quality around the time of ovulation and provides more of a physical sign. This discharge is normally clear and slippery.
Listen to your body
Your body might feel like it's going through odd changes that last for about 24 hours. You may have slight pain in your abdomen or mood swings.
The hormonal changes that signal your ovaries to release an egg can cause certain signs or symptoms. But these symptoms can also be helpful indicators of ovulation.
You may feel a twinge of pain or cramping. Known as mittelschmerz, or "middle pain "in German, this pain usually occurs each month from the left or right side of your lower abdomen, depending on which ovary is releasing the egg that month.
Changes in saliva
Estrogen and progesterone can change the consistency of dried saliva before or during ovulation, causing distinct patterns to form. But drinking, smoking, eating, and brushing your teeth can mask this change.
Basal body temperature (BBT), or your temperature when you first wake up in the morning, goes up or down by about 1°F during the 24-hour window after ovulation happens. If you don't become pregnant, your body will stay at that temperature until your period starts.
Changes in cervical mucus
Remember how we talked about discharge? Leading up to ovulation, you may end up seeing a change in your vaginal discharge because of the increase of this fluid in your cervix. This fluid thickens, increases, and sometimes takes on the consistency of egg whites. This mucus helps transport sperm to an egg.
How to track your ovulation cycle
There are a few different ways to track your cycle. But remember, everybody is different and external factors can influence your menstrual cycle, making it potentially tricky to be super precise. The most common forms of tracking your ovulation cycle include:
There are various calendars and trackers you can use to track your menstrual cycle, including the days leading up to ovulation.
Tracking the last day and first day of your periods can be an effective way to count down to ovulation. If your period happens every 28 to 30 days, ovulation will generally occur in the middle of that. But keep in mind that some people have menstrual cycles as short as 21 days and as long as 35—how you track comes down to your unique cycle.
Basal body temperature method
Take your oral temperature and track your BBT daily by recording it in a journal or an app. Take note of fluctuations before and during ovulation.
Cervical mucus method
Vaginal discharge is also another way to track your ovulation cycle. Secretions will change before ovulation to help prepare for potential sperm.
When to take a pregnancy test
It depends on when your period usually starts. However, periods aren't always consistent, so it can be hard to tell.
-If you regularly track your cycle and your period is a week late, take a pregnancy test.
-If you took Julie or another OTC morning-after pill, wait three weeks to see if your period arrives.
-If you didn't use an OTC morning-after pill, take a pregnancy test two weeks after sex.
When used as directed, Julie is safe and effective. Common side effects may include changes in your period, nausea, lower stomach pain, tiredness, headache, dizziness and breast tenderness. Julie will not protect you from HIV and other sexually transmitted diseases.
This article is for informational purposes only and does not constitute medical advice. The information contained herein is not a substitute for and should never be relied upon for professional medical advice. Always talk to your doctor about the risks and benefits of any medication