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If you have sex right before your period, it’s unlikely you’ll get pregnant, but it isn’t impossible.

In a perfect world, you would have a 28-day menstrual cycle, but because nature can’t seem to give us a break, your cycle can range anywhere from 21 to 45 days (and that’s still normal).

That means the day you ovulate (your most fertile day) can vary greatly, and yes, it could be right before your period. Here’s how to track if your next mattress dancing session is in the baby-making window.

Because charts say it best, if we broke down your chances of getting knocked up during your cycle, it would look something like this:

Chance of pregnancy during
time of cycle
Probs not
MaybeV likely
2 weeks before period (around ovulation) 👶
10 days before period (close to ovulation) 👶
5 days to 1 week before period 👶
2 days before period 👶
1 day before period 👶
During your period 👶
1 day after period 👶
2 days after period 👶
5 days to 1 week after period 👶
10 days after period (close to new cycle’s ovulation) 👶
2 weeks after period (around new cycle’s ovulation) 👶

Despite what everyone told you as a teenager, you can’t get pregnant every time you have unprotected sex. However, there is a 6-day window where you can conceive leading up to and on the day of ovulation.

Ovulation and the fertile window for beginners

If we were to look at the perfect menstrual cycle, it would be 28 days. The first day would be the day your period starts and the last day would be the day before your next period starts.

Your cycle has two phases: the follicular phase and the luteal phase.

During the follicular phase you have a period (which gets rid of the egg that didn’t get fertilized) and you ovulate around day 14 (when your new egg is released into the fallopian tube and ready for some swimmers).

After ovulation, you start the luteal phase, which is essentially when your body preps your cells and hormones for the next round.

Ovulation only lasts a whopping 12 to 24 hours, but sperm can survive for an estimated 5 days, meaning you have about a 6-day window to get pregnant (aka the fertile window).

This window includes the 12 to 24 hours of ovulation and the days sperm can live in the female reproductive tract. You are most fertile typically around 10 days to 2 weeks before your period, but there can be a lot of guesswork to figure out this window because it is not a one-size-fits-all approach.

Baby making: A game of chance

Figuring out when ovulation actually occurs is really dependent on your individual cycle. The Mayo Clinic says most women ovulate in the 4 days before or after the midpoint of the menstrual cycle.

A study from the National Institute of Environmental Health Sciences found women trying to get pregnant were more fertile right before or after the standard ovulation timing.

If you were to break down when women are most fertile based on this study, it would look like this:

  • 30 percent of women were most fertile on days 10 to 17 of their cycle.
  • 70 percent of women were most fertile before day 10 or after day 17 of their cycle.

Age also decides your chances of getting pregnant. If you’re under 25, you’re a fertile myrtle and it can be easier to preggo your eggo during the 5-day window. But, even then your chances of getting pregnant are pretty slim.

According to the American Society of Reproductive Medicine (ASRM), you are the most fertile in your 20s and it starts to slowly decline in your 30s (even more so after 35).

Here’s where that statistics class you didn’t go to would have come in handy. Your odds of pregnancy are low even if you are trying to get knocked up. ASRM notes that you only have a 20 percent chance of conceiving if you are a healthy, fertile 30-year-old trying to get pregnant.

If you’re outside of your fertile window or in the luteal phase of your cycle, chances are extremely low you’ll get pregnant. This is either because the egg is long gone or you’re totally out of the fertile window.

Right before your period

Once you’re outside your fertile window, you can’t get pregnant. About 1 or 2 days before your period starts would be way after you ovulate and therefore super unlikely you’d get pregnant.

During your period

We don’t judge you for some towel-down-period-sex. This is the part of your cycle you are least likely to get pregnant. At the beginning of your new cycle, there is no egg those little shooters can impregnate.

During your period you’re shedding the unfertilized egg from your previous cycle so you shouldn’t have or be close to having a fresh egg ready for baby-making.

Right after your period

It’s unlikely you’ll start your fertile window so early in your cycle, and therefore it’d be really rare to get pregnant right after your period.

Again, you usually don’t ovulate until around the middle of your cycle so the days right after your period would most likely not fall into your 6-day fertile window.

There are a few different ways to figure out when you’re in the baby-making phase (aka ovulation).

Cramping

As if period cramps weren’t enough, you can get ovulation cramps, too. When you’re ovulating you might get cramping similar to your period, but it will be way earlier than your period (about 2 weeks before your period or the middle of your cycle).

This is ovulation cramping — aka mittelschmerz. Some women have this pain when the ovary releases the egg and can last a few minutes to a few days.

Cervical fluid

Also, take a good look at your underwear. That discharge you see (or feel) at different times of your cycle is most likely cervical fluid (a fancy way to say normal vaginal discharge).

Fertile, quality cervical fluid helps transport sperm right to the egg like a slip-n-slide and is a great indication you’re in your fertile window.

Super fertile cervical fluid will be stretchy and clear like an egg white, and you might feel like you need to change your undies because things are getting pretty slippery down below.

Intermediate fertility can be identified by creamy or sticky cervical fluid that is white or yellow. Cervical fluid that has the lowest fertility is either nothing at all or just a little dampness. The female body’s weird, right?

A gross, but necessary tip for determining your cervical fluid is to just get in there yourself. Reach in, give it a swipe and look at the fluid on your fingers. If you’re really flowing, you’ll see it on your underwear or when you wipe.

Temperature

This might sound like an archaic method, but taking your basal body temperature (resting temperature) can help you pinpoint ovulation.

Charting your cycle using temperature and cervical fluid is a huge part of the Fertility Awareness Method (FAM), which some use to avoid and plan pregnancy.

For this to be accurate, you have to be consistent and take your basal temp every morning around the same time (with a basal temperature thermometer), and you can’t get out of bed.

As a basic rule, you are the most fertile 2 to 3 days before your temperature rises.

Ovulation tests

When you’re ovulating your body increases a hormone that you can test just like the pregnancy hormone. When the luteinizing hormone (LH) “surges” to high levels, this is an indication that your body is revving up for pregnancy.

When this hormone is the highest, you’re about 24 to 36 hours within ovulation range. Ovulation tests can help you figure out when you’re having an LH surge, and they come in strips, pee sticks, and digital tests just like pregnancy tests.

If you’re trying to avoid pregnancy, you don’t necessarily have to rely on figuring out when you’re the most fertile. You have a bunch of birth control options, which include:

  • Condoms and other barrier methods. The most accessible form of birth control are condoms, which prevent sperm from entering and help protect you from STIs. The less popular diaphragm, cervical cap, and sponge are also in this category.
  • Hormonal birth control. There are a bunch of hormonal birth control options out there that alter your hormones to prevent pregnancy. Hormonal birth control options include birth control pills, vaginal rings, contraceptive implants, birth control patches, and contraceptive injections will all help prevent pregnancy.
  • Intrauterine devices (IUDs). IUDs are implanted in the uterus and can prevent pregnancy for 3 to 10 years. Copper IUDs act like spermicide, while hormonal IUDs use hormones to prevent pregnancy.
  • Fertility awareness method (FAM) and symptothermal method. This falls under the natural family planning umbrella and includes keeping track of your cervical fluid and basal body temperature to identify when you’re most fertile to avoid pregnancy. To be successful in this method, you have to consistently monitor your cycle and make sure you use barrier methods like condoms or abstinence when you are most fertile. The rhythm method, which only uses a calendar method of tracking the days you think you’re fertile, is not an effective method compared to FAM or symptothermal.
  • Sterilization. Completely end your fertility or chances of conception. Women can get their tubes tied (tubal ligation) or tubal implants. Men can get a vasectomy.
  • The pull-out method. Having your partner “pull out” before ejaculation can prevent pregnancy, but it does have risks and isn’t a great form of birth control. It’s possible your partner doesn’t pull out in time or the precum contains sperm.

Remember, that outside of barrier methods, these birth control methods will not protect you from STIs and you should be tested regularly if you are sexually active.

Additionally, if you think you’ve just had sex during your fertile window and want to avoid giving birth to Junior in 9 months, you can take emergency contraception. This includes morning-after pills that can be taken within 5 days of unprotected sex or getting a Paragard IUD within the same timeframe.

tl;dr

  • It’s unlikely you’ll get pregnant right after, before or during your period.
  • There is only about a 6-day window where you can get pregnant.
  • Ovulation is the peak day of your fertile days and it varies per person.
  • Sperm is resilient AF. It can survive for 5 days waiting for the egg.
  • You’re most fertile around the middle of your menstrual cycle, which is 10 days to 2 weeks before or after your period.
  • Ovulation signs include cramps and stretchy egg-white cervical fluid.
  • Play it safe! Safe sex practices and contraception can help you prevent pregnancy.