Can you get pregnant right before your period?
It's unlikely but possible. In a typical cycle you ovulate about 12 to 14 days before your period, so the days just before it are usually not fertile. But ovulation can come later than expected, cycles vary, and bleeding you think is a period may not be. If you had unprotected sex and your period is late, take a pregnancy test.
Why the chance is usually low
You can only get pregnant during the fertile window: the roughly 6 days ending on ovulation day. The egg lives about 12 to 24 hours, and after ovulation the luteal phase lasts about 12 to 14 days before your period. So if ovulation happened on schedule, the last week before your period falls outside the fertile window.
Why it's still possible
- Late ovulation. Stress, illness, travel or an irregular cycle can push ovulation later, so the days you think are "right before your period" are actually fertile.
- Irregular cycles. If your cycle length varies, you can't know which days are just before your next period until it arrives.
- Unpredictable timing even in regular cycles. A study using hormone tests found women had at least a 10% chance of being in their fertile window on every day from day 6 to day 21, and some were potentially fertile in the fifth week of the cycle.
- Mistaken bleeding. Spotting or implantation bleeding can look like a light period, so a pregnancy may already have started.
| Timing of unprotected sex | General chance of pregnancy |
|---|---|
| During the 6-day fertile window | Highest, especially the 2 days before ovulation |
| A week or so before an expected period, regular cycles | Low, but not zero |
| Before an expected period, irregular cycles | Hard to estimate: ovulation may be later |
| During your period | Low, higher with short cycles. See pregnant on your period |
Counting days before your period is not a reliable way to avoid pregnancy. Lulu's predictions are estimates and Lulu is not contraception. If you don't want to get pregnant, use a proven method, and ask a pharmacist about emergency contraception if you had unprotected sex.
What to do now
- If you had unprotected sex in the last few days and don't want to be pregnant, ask a pharmacist or doctor about emergency contraception as soon as possible.
- Wait until the day your period is due. If it doesn't come, take a test.
- If you don't know when your period is due, test at least 21 days after the unprotected sex.
- If the test is negative and your period still hasn't come, test again a few days later.
Our pregnancy test calculator shows when a test is most reliable, and when to take a pregnancy test explains early tests. PMS and early pregnancy can feel alike: see PMS vs pregnancy symptoms.
See a doctor urgently if you could be pregnant and have one-sided pelvic pain, shoulder-tip pain, heavy bleeding, dizziness or fainting. These can be signs of an ectopic pregnancy.
Frequently asked questions
Can you get pregnant 2 days before your period?
It's unlikely if you ovulated on time, but possible if ovulation was late or your cycle is irregular.
Can you get pregnant a week before your period?
The chance is low in a regular cycle but higher if your cycles vary, because ovulation may happen later than you expect.
Is the week before your period a safe time?
No day is reliably safe. Ovulation timing varies even in regular cycles, so it isn't a dependable way to avoid pregnancy.
How soon could I test after sex before my period?
Most tests work from the first day your period is late. Testing earlier can give a false negative.
Sources
- Wilcox AJ et al. The timing of the fertile window in the menstrual cycle. BMJ (2000)
- NHS: Doing a pregnancy test
- NHS: Fertility in the menstrual cycle
- ACOG: Fertility Awareness-Based Methods of Family Planning
This page is for information only and isn鈥檛 medical advice. If something worries you, please talk to a doctor.
Keep reading
What is the fertile window?The fertile window is the 6 days ending on ovulation day when pregnancy is possible. How to estimate yours, the best days, and why it moves each cycle.Can you get pregnant right after your period?Can you get pregnant right after your period? Yes, especially with shorter cycles, because sperm can survive for days. How it happens and what to do next.Can you get pregnant on your period?Can you get pregnant on your period? It's possible but less likely. How sperm survival and early ovulation make it happen, with the real numbers.
When to take a pregnancy test: find your most accurate dayWhen to take a pregnancy test: enter your last period and cycle length to see the earliest testing day and the day a result is most reliable.
Luteal phase: why feelings get louderWhat the luteal phase is, how long it lasts, why progesterone rises and falls, and the common symptoms: PMS, cravings, low energy and mood changes.
Safe days calculator: why calendar safe days can't prevent pregnancyLooking for a safe days calculator? Here's why calendar safe days are unreliable as contraception, what the numbers say, and what works instead.