Most couples conceive within 6 to 12 months of trying. The highest chance of pregnancy happens in the very first month, with roughly a 30% conception rate per cycle. From there, the odds are cumulative: about 75% of couples conceive within six months, 90% within a year, and 95% within two years.
Those numbers assume regular unprotected intercourse, and they shift based on age, health, and timing. Here’s what affects your personal timeline.
What a Typical Timeline Looks Like
Fertility isn’t evenly distributed across the months you spend trying. Your best odds are right at the start: that first cycle carries roughly a 30% chance of conception. Each month after that, the per-cycle probability dips slightly for those who haven’t yet conceived, because the couples who get pregnant fastest are removed from the pool. By six months, three out of four couples have a positive test. By 12 months, nine out of ten do.
If you haven’t conceived after a full year, that doesn’t mean you won’t. About half of the couples who don’t conceive in year one will conceive naturally in year two, bringing the cumulative rate to 95%. The process simply takes longer for some people, and a longer timeline doesn’t automatically signal a problem.
How Age Changes the Odds
Age is the single biggest factor in how long conception takes, and its effect is more gradual than many people realize. Women in their mid-to-late 20s have the highest 12-month pregnancy rates, around 77 to 79%. Through the early 30s, the decline is modest: women aged 31 to 33 still reach about 77% at 12 cycles. The drop becomes steeper after 35, and by ages 37 to 39, the 12-month rate falls to roughly 67%.
The sharpest change comes after 40. Women aged 40 to 45 are about 60% less likely to conceive in any given cycle compared to women in their early 20s, and their 12-month pregnancy rate drops to around 55%. This doesn’t mean pregnancy is impossible in your 40s, but it does mean each cycle carries a lower probability, so the total timeline stretches.
Male age matters too, though the pattern is different. Men younger than 25 actually show reduced fertility compared to men in their early 30s, with a roughly 29% lower chance of conception per cycle. Beyond age 35, male fertility declines more gradually than female fertility, and researchers haven’t found a clear threshold where male age alone causes infertility.
The Fertile Window
Conception can only happen during a roughly six-day window each cycle: the five days before ovulation and the day of ovulation itself. The probability of pregnancy is highest on the last two or three days of that window and lowest on the first day. Outside this window, intercourse won’t result in pregnancy.
The tricky part is that this window shifts. Even among women with regular cycles, at least 10% were in their fertile window on any given day between cycle days 6 and 21. Only about 54% of women hit their peak fertility on the “textbook” days 12 and 13. Some ovulate as early as day 7, and a small percentage are still fertile well into the fifth week of a longer cycle.
Because pinpointing ovulation isn’t always reliable, the simplest strategy is to have intercourse every one to two days throughout the cycle. Couples who do this don’t need to track ovulation at all. Daily and every-other-day intercourse produce similar pregnancy rates, so either frequency works.
Coming Off Contraception
If you’re stopping birth control to try for a baby, you might wonder whether your method delays things. The short answer: for most methods, fertility returns quickly. About 83% of women conceive within 12 months of discontinuing contraception, regardless of the type.
Broken down by method, the 12-month pregnancy rates are roughly:
- Oral contraceptives (the pill): 87%
- IUDs: 85%
- Implants: 75 to 83%
- Injectable hormones: 78%
The differences between methods aren’t statistically significant, meaning no single type of contraception causes a meaningfully longer delay. Injectable users sometimes take a cycle or two longer to resume ovulation, but their 12-month rates still fall in a similar range. You don’t need a “waiting period” after stopping any of these methods before trying to conceive.
How Body Weight Affects Conception
Carrying significantly more weight increases the time it takes to get pregnant, primarily because excess body fat disrupts ovulation. Women with a BMI above 27 have roughly 2.4 times the risk of not ovulating regularly compared to women at a moderate weight. That risk climbs further as BMI increases, reaching about 2.7 times the risk at a BMI above 30.
The effect isn’t limited to ovulation. Higher BMI is also linked to lower implantation rates and a modestly increased risk of early pregnancy loss, about 1.3 times higher than for women at a moderate weight. Weight gain during adulthood appears to compound these effects, meaning your BMI trajectory over time matters, not just your current number.
Being significantly underweight (a BMI below 18.5) also raises health risks during conception and pregnancy, though the data on specific delays in time to pregnancy is less detailed. Reaching a moderate weight range before trying to conceive improves your odds from both directions.
When the Timeline Warrants a Checkup
The American Society for Reproductive Medicine recommends a fertility evaluation after 12 months of regular unprotected intercourse for women under 35, and after just 6 months for women 35 and older. The shorter window for older women reflects the steeper decline in per-cycle odds and the value of identifying treatable causes sooner.
These timelines assume no known conditions that could affect fertility. If you already know about irregular cycles, endometriosis, prior pelvic surgery, or a partner with known reproductive concerns, it’s reasonable to seek evaluation earlier rather than waiting out the full 6 or 12 months. About 10% of couples will meet the clinical threshold for an infertility workup, but many of them still go on to conceive with relatively straightforward interventions or simply more time.