How Long Does It Take to Get Pregnant? The Odds by Month and Age, and When to See a Doctor
In a German study of couples timing sex to the fertile window, 38% conceived in the first cycle, 81% by six cycles and 92% by twelve. The odds fall with age, especially from the late thirties, which is why the advice on when to get checked shifts from 12 months to 6.
By Kymata Health Editorial Published Last checked
We earn a commission if you buy through links on this page. It never changes our grades or rankings. How we make money →
This guide
Fertility & Prenatal- Question
- How long does it usually take to get pregnant, and when should we see a doctor?
- Sources
- 5 cited
- Quick answers
- 3 questions
- Clinician review
- None; sources cited inline
Key takeaways
4 points- Among 346 women timing sex with natural family planning, the chance of having conceived was 38% after 1 cycle, 68% after 3, 81% after 6 and 92% after 121.
- In 2,962 North American couples, the 12-cycle pregnancy rate ranged from 79.3% for women aged 25 to 27 to 55.5% for women aged 40 to 452.
- Nearly all pregnancies came from sex during a 6-day window ending on the day of ovulation, and the chance of conception from sex on a single day rose from 10% five days before ovulation to 33% on the day itself4.
- The CDC says women under 35 with regular cycles should try for at least a year before seeing a provider, women 35 or older should go after 6 months, and women over 40 should consider an evaluation sooner5.
Month by month: the first year
The cleanest numbers come from a German study that followed 346 women using natural family planning to conceive from their first cycle, timing sex to the fertile days1. The estimated chance of having conceived was 38% after one cycle, 68% after three, 81% after six and 92% after twelve; 10.4% of women did not conceive1. The authors concluded that most couples conceive within six cycles, and that after that, about every second couple is probably subfertile or infertile1.
These couples were tracking their fertile window, so the figures are close to a best case. In the US, the CDC reports that 19% of married women aged 15 to 49 with no prior births cannot get pregnant after a year of trying5.
How age changes the odds
In a North American cohort of 2,962 couples who had been trying for 3 cycles or less, the 6-cycle pregnancy rate ranged from 62.0% (women aged 28 to 30) to 27.6% (40 to 45), and the 12-cycle rate from 79.3% (25 to 27) to 55.5% (40 to 45)2. Compared with women aged 21 to 24, the chance of conceiving each cycle was 0.82 times as high at 34 to 36, 0.60 at 37 to 39 and 0.40 at 40 to 45, and it was fairly stable between 28 and 33; the drop was statistically clear from age 372. The authors reported no conflicts of interest2.
A cohort of women aged 30 to 44 with no known infertility found a similar pattern: compared with ages 30 to 31, the monthly chance of conceiving was 14% lower at 34 to 35, 30% lower at 38 to 39, 53% lower at 40 to 41 and 59% lower at 42 to 44, with the differences statistically clear from age 403. At every age, women who had never been pregnant had lower odds3.
Male age was not clearly linked to the odds after accounting for the woman's age, but few men in the North American study were over 452. The CDC notes that couples in which the man is 40 or older are more likely to report difficulty conceiving5.
Timing: the six-day fertile window
In a study of 221 women who collected daily urine samples, conception occurred only when sex took place in a 6-day window ending on the estimated day of ovulation4. The chance of conception was about 10% when sex happened five days before ovulation and 33% on the day of ovulation4. For tools that help find that window, see ovulation tests vs fertility apps.
If you recently stopped hormonal birth control, see how long it takes to get pregnant after stopping birth control.
When to see a doctor
The CDC's guidance for couples without known health or fertility problems is: if the woman is under 35 with regular cycles, try for at least a year; if she is 35 or older, see a provider after 6 months; if she is over 40, consider an evaluation and treatment sooner5. Both partners should be evaluated, because men and women can both contribute to infertility5.
- Do not wait if periods are irregular or absent, or if there is a history of endometriosis or very painful periods, pelvic inflammatory disease, known uterine or tubal disease, or more than one miscarriage5.
- Men should not wait if there is a history of testicular trauma, hernia surgery, chemotherapy, infertility with another partner, or sexual dysfunction5.
- Irregular cycles are a common sign of PCOS; see the PCOS hub.
Where to buy
Natural Cycles
Paid links · we earn a commissionAn app the FDA authorized in 2018 for women 18 and older to monitor their fertility, for preventing a pregnancy or planning one; it reads your temperature and cycle data to flag fertile days. It does not make you more fertile or guarantee a pregnancy. As birth control, the FDA reported a 6.5% typical-use failure rate, and the risk is higher if you used hormonal birth control in the previous 60 days. It does not protect against STIs.
See Natural Cycles (paid link, opens in new tab)
Quick answers
Questions
3 answersIs it normal not to get pregnant in the first month?
Yes. Even among couples timing sex to the fertile window, 38% had conceived after one cycle and 68% after three1.
Does age matter more for women or men?
In a North American cohort, the woman's age was strongly linked to the monthly odds, while the man's age was not clearly linked after accounting for hers2. Couples with a male partner aged 40 or older are more likely to report difficulty5.
When should we have sex to get pregnant?
During the six days ending on the day of ovulation; in a study of 625 cycles, nearly all pregnancies began in that window4.
More in Fertility & Prenatal
Keep reading
6 pages- Fertility & Prenatal hubEvery guide, regulatory notes and sources
- Prenatal Vitamins: What the Evidence Says About Folic Acid vs Methylfolate, Choline, DHA and Iodine
- CoQ10, Myo-Inositol and Other Fertility Supplements: What the Trials Actually Show
- Trying to Conceive? Medicines and Supplements to Stop or Review First
- How Long Does It Take to Get Pregnant After Stopping Birth Control?
- Ovulation Tests vs Fertility Apps vs Temperature Tracking: Which Helps You Get Pregnant?
Keep reading: Supplements and vitamins
Supplements and vitamins: every pageSupplement & Nutrient EncyclopediaBrowse all topics
- Previous in this topicHow Long Does It Take to Get Pregnant After Stopping Birth Control?About 83% of women were pregnant within a year of stopping contraception in a 22-study meta-analysis.
- Next in this topicOvulation Tests vs Fertility Apps vs Temperature Tracking: Which Helps You Get Pregnant?Urine LH ovulation tests are the only tracking method with randomized-trial evidence of more live births.
- Iodine (potassium iodide, kelp)Iodine is a trace mineral the thyroid needs to make the hormones T4 and T3, which regulate metabolism and early brain development.
- Methylfolate vs Folic Acid: What the MTHFR Gene Hype Gets WrongIf you have heard you "can’t process folic acid," you are not alone.
- Choline in Pregnancy: Most Women Fall Short, and Most Prenatal Vitamins Barely HelpAbout 9 in 10 pregnant women get less choline than the recommended intake, and prenatal vitamins rarely fill the gap.
References
Every study and document cited in this guide, numbered as in the text.
Sources
5 sources- 1Time to pregnancy: results of the German prospective study and impact on the management of infertility. Hum Reprod, 2003. PMID 12923157
- 2Age and fecundability in a North American preconception cohort study. Am J Obstet Gynecol, 2017. PMID 28917614
- 3Impact of female age and nulligravidity on fecundity in an older reproductive age cohort. Fertil Steril, 2016. PMID 26953733
- 4Timing of sexual intercourse in relation to ovulation. Effects on the probability of conception, survival of the pregnancy, and sex of the baby. N Engl J Med, 1995. PMID 7477165
- 5Infertility: Frequently Asked Questions. Centers for Disease Control and Prevention, 2024.
Dietary supplements are not intended to diagnose, treat, cure or prevent any disease, and these statements have not been evaluated by the FDA. Prescription options need a licensed clinician. Talk to your clinician or pharmacist before starting anything new, especially if you take prescription medicines, are pregnant or breastfeeding.