This question comes up in every gynecologist's office and on every forum. Can you really get pregnant during your period? Right before? Right after? The short answer is, Yes, it is possible at almost any time of the cycle., although the level of risk varies considerably. The risk is never exactly zero (unless medically impossible), and there is no such thing as a "completely safe period" without contraception. Sperm can survive for up to 5 days in the female reproductive tract, and ovulation is unpredictable, even with regular cycles. This article discussestaille the precise risk for each period of the cycle, with figures based on scientific studies, so you can make informed decisions.
The main thing to remember
- During menstruation : Low risk (1-5%) but exists, especially with short cycles or long periods
- Before menstruation : Very low risk (0,5-1%) if really at the end of the cycle, but difficult to confirm
- After menstruation : Medium to high risk (15-30%) as ovulation approaches quickly
- On sperm survive 5 days (sometimes 7) in a favorable environment
- Ovulation can vary from several days each month even with regular cycles
- The only reliable rule: contraception at all times of the cycle if unwanted pregnancy
- The calculation of "safe periods" (Ogino method) has a failure rate of 24% per year
Can you get pregnant during your period?
Direct answer: YES, it is possible
The risk is low (1 to 5%) but not zero. Pregnancy during your period is possible, especially if you have short cycles, long periods, or if you mistake ovulatory spotting for your period.
Theoretically, menstruation marks the beginning of a new cycle, far from ovulation, which typically occurs around day 14 of a 28-day cycle. However, several situations make pregnancy possible even during menstrual bleeding.
Why It's Possible: Sperm Survive
The determining factor is the survival of sperm in the female reproductive system. In a favorable environment (presence of cervical mucus), sperm can remain alive and fertilizing for up to 5 days, or even 7 days in rare cases.
Concrete scenario
You have intercourse on day 5 of your cycle (still menstruating). Sperm survive for 5 days, so until day 10. If you have a short 24-day cycle, you ovulate around day 10. Sperm are still there at the time of ovulation → pregnancy possible.
Risky Situations During Menstruation
- Short cycles (less than 25 days) : If your cycle is 21-24 days long, ovulation occurs as early as day 7-10. Intercourse at the end of your period (day 5-6) may coincide with the sperm survival period.
- Long periods (7 days or more) : A period that lasts a week automatically brings the end of bleeding closer to the ovulation period.
- Unusual early ovulation : Stress, travel, illness, or a change in routine can delay ovulation by several days, including earlier than expected.
- Confusion with ovulatory spotting : About 5% of women experience light bleeding around the time of ovulation. If you mistake this bleeding for your period, you are in your fertile period.
Quantified Risk Level
Estimating the risk of pregnancy during menstruation
- Standard 28-day cycle, normal period (5 days): 1-2% risk
- Short cycle of 21-24 days: 3-5% risk
- Long periods (7+ days): 2-4% risk
- Long and regular cycle (30-35 days): almost zero risk (less than 0,5%)
Can You Get Pregnant Before Your Period?
Direct answer: VERY LOW risk (0,5-1%)
If you are truly at the very end of your cycle (1 day before your period), the risk is extremely low. Ovulation occurred about 14 days earlier, and the egg is no longer fertilizable. However, it is difficult to know for sure that you are truly one day before your period.
At this point in your cycle, you are normally in the very late luteal phase. Ovulation has already occurred about 12 to 14 days ago, and the egg is no longer viable (it only survives for 12 to 24 hours after ovulation).
Intercourse just before your period?
Find out the true level of pregnancy risk
Risk of pregnancy BEFORE period →Why the Risk is So Low
End-of-cycle physiology
- The egg released during ovulation only lives for a maximum of 12 to 24 hours
- The luteal phase (between ovulation and menstruation) lasts 12 to 16 days in most women
- Just before menstruation, progesterone and estrogen levels drop sharply
- The endometrium begins to disintegrate, the environment is no longer favorable for implantation
- Even if sperm survive for 5 days, there are no more eggs to fertilize.
The Problem: Knowing That We Are Really One Day Away
The major difficulty is that it is almost impossible to know for sure that you are exactly 1 day away from your period, unless you rigorously track your cycle with several biomarkers (basal temperature, cervical mucus, ovulation tests).
Situations where risk increases
- Irregular cycles : If your cycles vary from 25 to 35 days, you can never be sure when your period will arrive.
- Confusion with premenstrual bleeding : Some women experience light spotting 2-3 days before their actual period.
- Delayed ovulation : If your ovulation has been delayed this month (stress, illness), you may not be at the end of your cycle as you think.
- Rare double ovulation : In very rare cases, a woman may ovulate twice in the same cycle.
Estimation of Real Risk
If you are absolutely certain that you are 1 day away from your period (confirmed by basal temperature, negative LH test for 12 days, dry cervical mucus), the risk is 0,5 to 1%.
However, if you base this estimate solely on the calendar and a "regular" cycle, the actual risk is more difficult to assess and could be slightly higher (2-3%) due to the possibility of error in the actual date of the period.
Can You Get Pregnant After Your Period?
Direct answer: YES, MEDIUM TO HIGH risk (15-30%)
This is the period when the risk becomes truly significant. As early as 7 days after the start of your period, you enter your fertile window. The further you are from the end of your period, the greater the risk, as ovulation approaches.
This period is particularly misleading because many women think they are "far from ovulating" right after their period. In reality, this is exactly when the fertility window opens.
Why the Risk is High
The fertility window starts early
- In a 28-day cycle, ovulation occurs around day 14
- Sperm survive for 5 days, so the fertile window begins on day 9
- If your period lasts 5 days, you are on day 7-8 just after it ends
- There are only 1 to 2 days left before the actual fertile period begins
- Your body is already starting to produce fertile cervical mucus which helps sperm survive
Risk by Cycle Type
The Role of Cervical Mucus
As soon as your period ends, your body begins producing cervical mucus under the influence of estrogen. This mucus plays a crucial role in sperm survival.
Changes in cervical mucus after menstruation
- Journeys 1-5 : Menstrual bleeding, no observable mucus
- Journeys 6-8 : Thick, sticky, whitish mucus (unfavorable)
- Journeys 9-12 : Creamy mucus then increasingly liquid (favorable)
- Journeys 12-14 : Clear, elastic, "egg white" mucus (very favorable)
- This fertile mucus can extend sperm survival by up to 7 days in rare cases
Concrete High Risk Scenario
Real example
You have a 26-day cycle. Your period lasts 5 days. You have intercourse on day 7 (2 days after your period ends).
- Expected ovulation: day 12 (26-14 = 12)
- Sperm can survive: from day 7 to day 12
- Result: Sperm are still alive at the time of ovulation
- Risk of pregnancy: approximately 20-25%
Are you trying to conceive?
Calculate your fertile window after your period
Optimize your chances of pregnancy →Comparison Table: Pregnancy Risk by Period
Why Risk Is Never Zero
Even with all this information, it's impossible to define a "completely safe period" without contraception. Two biological factors make the risk persistent at almost all times.
1. Sperm Survival Is Variable
Scientific studies show that sperm survival time depends on the cervical environment. In an optimal environment (fertile cervical mucus, favorable pH), they can survive:
- 3 days : average survival time
- 5 days : common in good conditions
- 7 days : rare but documented in several studies
- You cannot predict in advance how long sperm will survive in your body.
2. Ovulation is unpredictable
Even in women with regular cycles, the date of ovulation can vary by 3 to 5 days from month to month. Factors that can delay ovulation include:
- Emotional or physical stress : can delay ovulation by several days
- Illness or infection : fever, flu, urinary tract infection
- Travel and jet lag : disrupts circadian rhythms
- Rapid weight change : loss or gain of several kilos
- Unusual intensive sport : marathon, competition
- pharmaceuticals : certain antibiotics, anti-inflammatories
- Natural hormonal changes : premenopause, postpartum
The Ogino Method (Calendar): Why It Doesn't Work
The calendar method, also known as the Ogino method or the Days Method, involves calculating your "safe periods" based solely on your usual cycle length. It is one of the least reliable contraceptive methods available.
Failure Rate of the Ogino Method
Scientific data on effectiveness
- Failure rate in typical use: 24% annually
- Failure rate in perfect use: 5% annually
- This means that out of 100 women using this method for 1 year, 24 will get pregnant
- It is 12 times less effective than the contraceptive pill (failure rate 2%) and 30 times less effective than an IUD (failure rate 0,8%).
Natural Contraception Methods That Work (Better)
If you don't want to use hormonal or mechanical contraception, there are natural family planning (NFP) methods that are more effective than the simple calendar, but they require careful observation of several biomarkers.
Symptothermal method, when practiced perfectly and with rigorous monitoring, can achieve an effectiveness rate comparable to the pill. However, it requires several months of training, meticulous daily observation, and remains less reliable than modern methods of contraception.
Protect yourself throughout your cycle
Period Panties provide comfort during your period, but they are not a substitute for contraception. To avoid unwanted pregnancy, use reliable contraception at all times during your cycle.
What to Do If You Have Had Unsafe Sex
If you have had unprotected sex and do not want to become pregnant, there are several emergency contraception options available depending on how long it has been since intercourse.
Emergency Contraception: The Options
Morning-after pill (levonorgestrel)
- Effective up to 72 hours after intercourse (ideally within 24 hours)
- Available without a prescription in pharmacies
- Effectiveness: 85% if taken within 24 hours, 60% between 48-72 hours
- Less effective in women over 75kg
EllaOne Pill (ulipristal)
- Effective up to 120 hours (5 days) after intercourse
- Requires a prescription
- Effectiveness: 95% if taken within 24 hours, remains effective beyond that
- Efficacy maintained even in overweight women
Emergency copper IUD
- Effective up to 5 days after intercourse
- Requires a gynecological consultation for installation
- Effectiveness: 99,9% (most effective method)
- Bonus: Can stay in place for long-term contraception
The Only Reliable Rule: Contraception at All Times
If you've taken away one thing from this article, let it be this: the risk of pregnancy exists at almost every point in your cycle, even during your period. Yes, the risk level varies considerably between "during" (1-5%), "before" (0,5-1%), and "after" (15-30%) your period. But "low risk" does not mean "no risk."
Sperm are survivors, ovulation is fickle, and your body doesn't follow a perfect calendar month after month. If you don't want to get pregnant, the only reliable strategy is to use effective contraception at all times of your cycle. Calendar and "safe days" calculations are not viable contraceptive methods, with a failure rate of 24% per year. Talk to your gynecologist or midwife to find the right contraception for you, and always keep emergency contraception on hand in case you forget to use it or have an accident.
Sources & Scientific References
This article is based on published scientific studies and international public health data.
Studies on the fertile window and sperm survival
- Wilcox AJ, Weinberg CR, Baird DD. (1995). Timing of sexual intercourse in relation to ovulation. Effects on the probability of conception, survival of the pregnancy, and sex of the baby. New England Journal of Medicine. DOI: 10.1056/NEJM199512073332301
- Colombo B, Masarotto G. (2000). Daily fecundability: first results from a new data base. Demographic Research. DOI: 10.4054/DemRes.2000.3.5
Effectiveness of natural contraceptive methods
- Trussell J. (2011). Contraceptive failure in the United States. Contraception. DOI: 10.1016/j.contraception.2011.01.021
- Frank-Herrmann P, et al. (2007). The effectiveness of a fertility awareness based method to avoid pregnancy in relation to a couple's sexual behavior during the fertile time: a prospective longitudinal study. Human Reproduction. DOI: 10.1093/humrep/dem003
Emergency contraception
- WHO. (2024). Emergency contraception fact sheet. World Health Organization. WHO
Note: DOIs allow direct access to original scientific publications.
Medical Warning: This article is for informational purposes only and is not a substitute for professional medical advice. To choose contraception that is right for you, consult a gynecologist or midwife.
1 comment
I want to get pregnant and have a baby.