SKIP AHEAD. . .
Can you get pregnant on your period?
To be clear, the chances of getting pregnant on your period are pretty low. Ovulation typically occurs early enough in the cycle that the fertile window (and more about that below) has closed by the time you start bleeding, meaning that there is no egg available for fertilization (which is kinda key to getting pregs!) and progesterone levels, which are especially important for carrying out a pregnancy, drop significantly.
However, it is possible to get pregnant on your period if a whole bunch of factors lineup, particularly for those with very short cycles (generally between 21-24 days long). In the “average” menstrual cycle—whatever that means—there is a big enough window between bleeding and ovulation so that the fertile window doesn’t overlap with your period. However, if you have a shorter cycle, this window can be smaller and potentially overlap, making pregnancy possible during the time you are bleeding. Also, if your cycle is irregular it can put you at higher risk of getting pregnant during your period due to the potential for inconsistency around time of ovulation and variance in hormone levels.
Okay, so what is this fertile window I keep talking about? The fertile window is the period of time during a cycle when you’re able to get pregnant, and it’s due to a few factors: The quality of cervical fluid, timing of penetrative vaginal sex, sperm lifespan in the body, time of ovulation, and lifespan of egg once released. Because sperm can live inside of the body for 3-5 days in fertile cervical fluid (2), if you had penetrative sex at the end of your period and you ovulated within a few days and the sperm survived for long enough, you could technically get pregnant.
In other words, even though the egg would be fertilized after your cycle ends, the sperm doing the fertilizing would be from penetrative sex that happened during your period. Translation? If you’re not looking to get pregnant, you still want to use birth control while you’re bleeding.
Can you get pregnant right after your period?
Yes! Because you can ovulate anywhere from days 6-21, it’s possible to get pregnant closely following your period for the same reasons as above (2). If you bleed for 5-7 days, have fertile cervical fluid that enables the sperm to survive long, and ovulate on the earlier side, you could become pregnant.
And that also means that you can get pregnant right before your period too, right?
Yep, that too! However, this is probably the most unlikely of all the times in your cycle. Similar to the questions of getting pregnant on or right after your period, the window between ovulation and your period is generally long enough that you won’t get pregnant right before. The egg can only survive for 12-24 hours once it’s released, so once that window has passed, there is no way for pregnancy to occur until the next time you ovulate. In a cycle of 28-30 days or longer, ovulation occurs between days 11 and 21, but it is possible to ovulate later in your cycle, particularly if you have short cycles.
How to track ovulation
Tracking ovulation can be tricky and confusing, especially if you’re tracking it to achieve or avoid pregnancy. There is only a small window of time during each cycle when pregnancy is possible, which is during ovulation and the aforementioned fertile window. Ovulation occurs when a mature egg is released from a follicle into the fallopian tube. If sperm is present during the 12-24 hours when an egg can survive after being released, the egg may be fertilized, otherwise it disintegrates into the body and the cycle repeats.
Most period tracking apps are designed with the average 28-day cycle in mind, with ovulation occurring on the 14th day. But in reality, it’s very likely that you actually don’t ovulate on day 14 of your cycle, or at least not consistently. According to one study, only 10% of menstruating people ovulated on the 14th day of their cycle (3). For everyone else, ovulation may occur anywhere between days 6 and 21. (This fertility tracker actually gets smart to your personal cycle!)
All cycles look a little different and can be impacted by external factors like stress, sleep, illness, diet, alcohol, antibiotics, and hormonal changes. It’s not possible to determine exactly when you ovulate, but there are ways to confirm ovulation has occurred. If you learn to track your cycle each month, you may be able to eventually notice patterns consistent to your specific cycle that give you an idea of when you ovulate. After observing these patterns for a few cycles, you’ll be able to determine if you’re one of the people who may be at risk of getting pregnant close to or on your period.
Tracking ovulation can be done with the help of two main physiological signs, which the Fertility Awareness Method teaches you how to interpret:
Basal Body Temperature
Your basal body temperature (BBT) is your waking temperature, aka your temperature that’s taken prior to getting out of bed, peeing, brushing your teeth, drinking water, etc. This can be taken with a basal body thermometer, which you can find at a drug store or online. Your BBT fluctuates throughout your cycle, with certain changes indicating various hormonal shifts. Following ovulation, your BBT rises due to rising levels of progesterone. The rules can be complicated, but you’re looking for a thermal shift, or a temp 2/10ths higher than your last six consecutive temps, to confirm ovulation.
Cervical fluid can tell you a lot about your body! The color and consistency changes due to hormonal fluctuations throughout your cycle, which can help you figure out your fertile window. When you’re fertile, you’ll notice cervical fluid that is stretchy and viscous, similar to raw egg whites. This is the fluid that allows for optimum motility of sperm and is what enables sperm to survive up to 5 days in your body.
You also may notice symptoms like breast/chest tenderness, sensitive nipples, spotting, bloating or acne around the time of ovulation, which you can take note of and keep track of in an app or notebook (4).
Birth control methods
Like we previously mentioned, if you don’t want to get pregnant, it’s a good idea to protect yourself even during your period. Here, all of your options for birth control (5):
- Condoms: There are internal and external condoms and both serve as barriers between semen and the vagina. Effectiveness: 85% (external), 79% (internal), Cost: $0-$3
- Diaphragm: This is a flexible, dish-shaped silicone cup that is used with spermicide and placed inside of the vagina during sex, covering the cervix and blocking sperm. Effectiveness: 88%, Cost: $0-$75
- Cervical cap: A cervical cap is similar to a diaphragm in function but smaller and shaped like a sailor’s hat. It’s also used with spermicide to increase effectiveness and it comes in three sizes. Effectiveness: 71%-86%, Cost: $0-$90.
- Sponge: This BC is a soft, plastic sponge that is inserted into the vagina and covers the cervix. The sponge contains spermicide for increased effectiveness. Effectiveness: 76%-88%, Cost: $0-$15
Most hormonal forms of birth control deliver synthetic versions of these two hormones called estrogen and progestin. They work by suppressing ovulation and thickening cervical fluid (making it harder for sperm to survive and travel to the egg) to prevent pregnancy. However, estrogen isn’t recommended for those with a history of high blood pressure, strokes, blood clots, heart attacks, migraines or increased risk of breast cancer. Here are the birth control options with estrogen and progestin:
- Combination Pill: The classic birth control pill, taken daily at the same time. Effectiveness: 91%, Cost: $0-$50
- Patch: The patch is worn on the skin for three weeks, off for a week, and then replaced with a new one. Effectiveness: 91%, Cost: $0-$150
- NuvaRing: This BC method is a small, flexible ring inserted into the vagina for three weeks and taken out for one. Effectiveness: 91%, Cost: $0-$200
- Implant (Nexplanon): The implant is a thin, flexible rod inserted into the arm by a health provider, and it’s good for up to five years. Effectiveness: 99%, Cost: $0-$1300
There are also some hormonal birth control options that come without synthetic estrogen, and these work by suppressing ovulation and thickening cervical fluid. Here are Progestin-only BC options:
- Mini-Pill: The classic birth control pill, taken daily at the same time. This version of the pill is a better choice for those sensitive to synthetic estrogens and those breast/chestfeeding.
- Injection (Depo-Provera): Hormones are delivered via injection by a health provider every three months. Effectiveness: 94%, Cost: $0-$100
- Hormonal IUD: A t-shaped device that is inserted into your uterus by a care provider. There are a few different brands that work for varying durations ranging from 3-7 years. Effectiveness: 99%, Cost: $0-$1300
- Copper IUD (Paragard): This IUD is similar to the hormonal IUD but is free of hormones. Instead, it is wrapped in copper, which is toxic to sperm, and lasts up to twelve years. Effectiveness: 99%, Cost: $0-$1300
- Withdrawal (Pull-out method): This birth control method involves removing the penis from the vagina, prior to ejaculation. Remember, any amount of semen that gets into the vagina can result in pregnancy so it’s important to really know your sexual responses and fully trust your partner. Withdrawal can be used with condoms for increased effectiveness. Effectiveness: 78%, Cost: free!
- Fertility Awareness Method: As previously discussed, the fertility awareness method uses basal body temperature and cervical fluid to track your cycle. This is not the same as natural family planning or the rhythm method. With perfect use, it’s 95%-99% effective, but it can take some time to get the hang of and should be used with other non-hormonal methods while you’re learning. There are also devices like Daysy and Ava Fertility Bracelet, which utilize FAM to determine fertility status. Effectiveness: 76%-99% (depends heavily on adherence to various rules), Cost: free, however, varies depending on what resources people choose to utilize for support (i.e. books, practitioners, apps).
Note: Costs vary depending on insurance and accessibility to free community resources. Effectiveness varies depending on usage and individual factors. You can find more information about each of the methods here and here.
Written by: Paige Green, @pagpaggy, reproductive health educator and full spectrum doula
Medically reviewed by: Aisha Williams, RN
All content found on this Website, including: text, images, audio, or other formats, was created for informational purposes only. The Content is not intended to be a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition.
(2) Weschler, Toni. 2015. Taking Charge of Your Fertility: The Definitive Guide to Natural Birth Control, Pregnancy Achievement, and Reproductive Health. New York: William Morrow, an Imprint of HarperCollins.
(3) Wilcox, A. J., Dunson, D. D., Blaird, D. D. 2000. “The timing of the “fertile window” in the menstrual cycle: day specific estimates from a prospective study.” BMJ (Clinical research ed.) vol. 321 (7271), 1259-62.