Your birth control pill, implant, or IUD gives you control of your future. These methods help women control their cycle, avoid pregnancy, and stabilize their hormones.
It’s no wonder that over 50% of American women of childbearing age use prescription contraceptives.
Yet despite its widespread use, few women understand how birth control works. Let’s talk about how common methods of birth control prevent pregnancy.
We’ll also answer the question: do you ovulate on birth control?
Reversible methods of birth control not only prevent pregnancy, but they give women the option of getting pregnant in the future.
These include Intrauterine Devices (IUDs), birth control pills, implants, rings, and patches.
Surgical methods, like tubal ligation (or “getting your tubes tied”) are permanent.
In this article, we’ll talk about reversible contraception.
For many women, just knowing that their birth control has a 90+% effective rate is enough.
But understanding birth control can help you weigh the pros and cons of different methods. It can also help you plan for PMS and your periods (if you still get them).
Ovulation happens 12-14 days before your next cycle, when a follicle in your ovary releases an egg.
If that egg meets a sperm, fertilization happens.
Then the fertilized embryo attaches to the uterine wall during implantation. But do you still ovulate on birth control? Let’s talk about it.
Whether or not you still ovulate depends on what form of birth control you’re using.
Most contraceptive methods suppress the release of an egg. Some prevent pregnancy by different means. Take a look at the most common forms of birth control and whether they prevent ovulation:
Preventing egg release stops the opportunity of fertilization. But there are other ways that birth control can prevent pregnancy.
Let’s back up and talk about how birth control works.
Depends on the type of birth control. Here are the two broad categories:
1. Hormonal contraceptives work by influencing the chemical signals that regulate your monthly cycle. Most of them stop you from ovulating. They’re generally very reliable.
But because they affect your hormones, they may have side effects.
Birth Control Pills, patches, rings, implants, and hormonal IUDs are all hormonal contraceptives.
2. Non-hormonal contraceptives prevent pregnancy through other means. This may include making the vaginal canal inhospitable to sperm, like Copper IUDs.
Other forms of non-hormonal contraceptives include diaphragms and condoms. These methods are less effective, but they’re used only during sex. They work by stopping sperm from entering the vagina.
Individual types of birth control work differently from one another. Birth control pills are the most commonly prescribed contraceptive worldwide.
But how do they work? Let’s talk about oral contraceptives.
Birth control pills come in two broad categories: combination and progestin-only (mini pills).
Of the two, combination pills are more common. If used correctly, both forms are really good at preventing pregnancy.
If you take it every day, you have less than a 1% chance of getting pregnant in a month.
This is because birth control pills prevent pregnancy through three separate mechanisms:
Oral contraceptives stop an egg from being released from your ovary. They do this by using progestin, or progesterone.
Not only does progestin prevent you from ovulating, it goes back one extra step. Progestin prevents an egg from maturing in the first place.
During the follicular phase, progestin in birth control pills prevents egg maturation. Progestin stops the hypothalamus from pulsing your gonadotropin-releasing hormone (GNRH).
This in turn suppresses Follicle-Stimulating Hormone (FSH). And without FSH, a follicle never matures.
Along with FSH, progestin also suppresses LH, or luteinizing hormone. The surge of LH in your cycle causes an egg to release from a follicle. But with LH suppressed, ovulation won’t happen.
Estrogen also has some effect in preventing follicle development and ovulation. It works on the anterior pituitary to slow down FSH secretion. This also prevents an egg from maturing.
In a normal cycle, cervical mucus thins around ovulation. This helps the sperm travel up the vagina, into the uterus, and to the fallopian tube.
But when you take birth control, it changes your cervical mucus.
The estrogen in birth control pills causes your cervical mucus to thicken. This makes it inhospitable to sperm.
Instead of being able to swim through it, sperm get caught in cervical mucus at the entrance to the uterus. This prevents them from reaching the fallopian tubes for fertilization.
If you’re not on birth control, your uterus spends the follicular phase preparing for implantation. The inner lining of the uterus grows thicker and more vascular. This makes for a hospitable environment for a fertilized egg.
When you’re on birth control, estrogen and progesterone stop this from happening.
Instead of growing thicker, the uterine lining stays thin. So even if an egg matures, gets released, and fertilized, the endometrium is still an inhospitable place for it to implant.
In a normal cycle, you’d be shedding your uterine lining during your period. But you haven’t built up any extra endometrium, so why can you still have a period on birth control?
If you’re on hormonal contraceptives, you may still have a period because of withdrawal bleeding.
Birth control pills include placebo, or sugar pills, during the last week of your cycle. There is no progestin or estrogen in these last few days of pills, so you may have a light period in the last few days of your cycle.
Other forms of hormonal birth control work in the same way as pills. IUDs, patches, rings, and implants are different ways of delivering progestin and estrogen in daily doses.
These methods can be better options for women who have trouble taking a birth control pill at the exact same time every day.
Hormonal methods like these mostly prevent ovulation. But if you’ve missed your pill for a day, or taken it at the wrong time, you may still ovulate.
For some women, birth control methods don’t totally prevent ovulation even when used 100% correctly.
These instances of break-through ovulation can lead to pregnancy, even if you’re on a birth control pill.
Here’s how to tell if you’re ovulating on birth control.
Pay attention to any of these ovulation symptoms if you’re on birth control:
Most forms of birth control stop ovulation from happening. Some forms will still let you ovulate, including Mini Pills, some IUDs, and copper IUDs.
If you’re on one of these methods, you can usually expect to ovulate on a normal schedule.
Ovulation happens right in the middle of your cycle, day 15 on average for a 28-day cycle.
But there’s a wide spread around ovulation time: some women will have theirs as early as day 9, and as late as day 23 based on their cycle length. This is because ovulation typically occurs about 12-14 days before your next period.
Learn More About : When Do you Ovulate?
If you do ovulate on birth control, it will most likely fall in the middle of your cycle. On average, women ovulate on day 15 in a 28-day cycle.
The average menstrual cycle is 28 days long, but cycle lengths vary. Some women will have cycles as short as 21 days, and some are as long as 35. And your cycles can vary a lot month-to-month, too.
The upshot of all this variation is that paying attention to symptoms of ovulation can help you prevent getting pregnant. Even if you’re on birth control, noticing thinning cervical mucus can help you clue-in to breakthrough ovulation.