If someone ovulates soon after their period ends, then has sex in the days around ovulation, they could become pregnant.

It is theoretically possible to get pregnant at any point in the menstrual cycle, especially if their cycle is often irregular. This means they could become pregnant before, during, or straight after a period.

This article explores how it is possible to get pregnant right after a period, factors that increase the chances, and how to prevent unplanned pregnancy.

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A person can get pregnant right after their period.

For this to occur, they have to have sex near the time of ovulation, which occurs when the ovaries release an egg.

The closer to their period a person ovulates, the higher their chances of becoming pregnant right after a period. And the closer to ovulation that a person has sex, especially if they have sex before ovulation, the higher the odds of pregnancy.

A 2019 study used data about more than 225,000 periods from a fertility monitoring app. The study found that a person may get pregnant by having intercourse from 7 days before ovulation up to 1 day after ovulation.

Most females ovulate toward the middle of their menstrual cycle, around day 14 and almost always before day 20.

Day 1 of a person’s menstrual cycle is always the first day of their period, so the average person’s ovulation occurs around 2 weeks after their period starts.

For a person whose ovulation timing hovers near the average, it would be possible to get pregnant by having sexual intercourse as early as day 7, right after a period, and sometimes while still bleeding.

Therefore, for people who do not wish to conceive but want to have sex during this time, it is still important to use birth control.

However, it is important to note that becoming pregnant at this time is unlikely. Therefore, for people trying to conceive, it is better to have sex around 12–14 days before the next period begins.

A 2019 study used data from a fertility app to compare more than 600,000 menstrual cycles. It found that people with very short cycles usually ovulate around day 10. However, it is important to note that the study took place in a group of around 600,000 people, and this particular effect occurred in fewer than 1% of cases.

Someone with a short cycle who had sex in the days leading up to the moment of ovulation could theoretically get pregnant as early as 3 days after the start of their period.

Anyone can become pregnant right after their period.

A 2018 article found that a healthy person’s cycle can vary by up to 9 days a year. Therefore, even someone who normally ovulates around day 17 or 18 might occasionally ovulate much earlier.

A person may be more likely to become pregnant during or right after their period if they:

  • frequently have unprotected sex
  • have a very short or irregular menstrual cycle
  • are over the age of 40 years and approaching menopause. A 2002 study found that women aged 40–45 ovulated slightly earlier in their cycles than younger women.

The chances of becoming pregnant vary from person to person and from cycle to cycle.

On average, a 30-year-old person’s odds of getting pregnant are about 20% per cycle, assuming they are having unprotected sex.

By the time someone is 40, the figure is less than 5% on average. However, individual fertility varies greatly, so some 40-year-olds may be significantly more fertile than some 25-year-olds.

The odds of becoming pregnant also depend on when a person has sex relative to ovulation. An app-based study of people who were trying to get pregnant found the average chances of pregnancy were as follows:

Timing of sex relative to ovulationAverage chance of pregnancy
7 days before ovulation 3%
6 days before ovulation 6%
5 days before ovulation 9%
4 days before ovulation 18%
3 days before ovulation27%
2 days before ovulation33%
1 day before ovulation 42%
the day of ovulation 20%
the day after ovulation8%

Therefore, people should not rely on when their period is due to decide whether to have sex.

The most crucial factor is ovulation. A period indicates the beginning of a new cycle, but it reveals little about when a person might ovulate.

The most effective strategy for avoiding pregnancy is to refrain from sex. Sexually active people who do not wish to become pregnant should use contraceptives such as condoms or birth control.

Using two methods can offer additional protection, for example, when a person uses both hormonal birth control and condoms.

Several fertility monitoring techniques make it easier for a person to pinpoint their fertile window and avoid sex or use contraceptives during this time.

These methods are more effective if a person has regular periods. Some fertility monitoring strategies include:

  • Charting basal body temperature: A person’s morning body temperature usually rises shortly after ovulation.
  • Using ovulation predictors: These tests typically give a positive result a day or two before ovulation, but it is possible to get a positive without ovulation.
  • Looking for fertile cervical fluid: Thick cervical fluid with a texture similar to raw egg whites indicates ovulation is approaching.
  • Checking cervical position and texture: Some females find that the position and texture of their cervix changes throughout their cycle.

The most reliable pregnancy symptom is a missed period followed by a positive pregnancy test.

Many pregnant people do not have symptoms early in the pregnancy, just as many people who are not pregnant have symptoms such as nausea and vomiting.

Some potential early pregnancy symptoms include:

  • nausea
  • vomiting
  • dizziness
  • fatigue
  • aversions to certain foods and smells
  • breast pain
  • more frequent urination

Home pregnancy tests are reliable, especially if a person waits until the day their period is due.

If the test is negative, try waiting a few days. This gives levels of the pregnancy hormone human chorionic gonadotropin (HCG) time to rise, increasing the likelihood of a positive result.

A doctor or midwife can test for pregnancy using blood or urine tests that may be more sensitive than a home pregnancy test. It is not typically possible to see a developing baby on an ultrasound until several weeks into the pregnancy.

A doctor or midwife can test for pregnancy, check for normal fetal development, and advise about early pregnancy health.

A healthcare provider can also help discuss a person’s options for managing an unintended pregnancy.

Pregnancy is not an emergency, and it is safe to wait a few weeks to speak with a healthcare provider unless a person wants to monitor HCG levels or has pregnancy-related health questions.

Call a healthcare provider if a person experiences:

  • intense abdominal pain
  • bleeding during pregnancy
  • nausea so severe that they are unable to keep down any food

The timing of a person’s period does not have much to do with when they can become pregnant.

Moreover, a person can have bleeding from something other than their period.

Therefore, counting the days after a period is not an accurate way to determine the likely time a person might get pregnant.

It is safer trying to pinpoint the likely time of ovulation, as well as the days of fertility that come before and after.