Trying to conceive · 5 min · sourced
Most pregnancies occur within the first six cycles with intercourse in the fertile phase (about 80%); after that, serious subfertility must be assumed in about every second couple1. One review of fertility data found that most pregnancies occur within the first six cycles of well-timed intercourse (about 80%), and that after 12 unsuccessful cycles untreated live birth rates still reach nearly 55% over the next 36 months1.
Many couples who haven't conceived by 6 months conceive naturally in the following 6 months without medical help1. Most pregnancies occur in the first six cycles with well-timed intercourse (about 80%), and after 12 unsuccessful cycles, untreated live birth rates in the following 36 months still reach nearly 55%1.
The studies include couples with and without perfect timing. Confirmed ovulation and good timing prove one piece is working, but conception depends on factors beyond what timing can control.
In one study of healthy women trying to conceive, the chance of conception ranged from about 10% to 33% depending on the timing of intercourse relative to ovulation, and conception occurred only when intercourse fell within a six-day window ending on the day of ovulation2.%. ).
The fertile window is 6 days ending on ovulation day2. Day-specific conception probabilities range from 10% five days before ovulation to 33% on ovulation day itself2. Even intercourse on ovulation day gives you about a 1-in-3 chance that month2.
Conception requires more than ovulation and timing. The egg must be of sufficient quality. Sperm must reach and fertilize it. The embryo must develop correctly and implant successfully. Tubal function must allow transport. Any one of these steps can fail in a given cycle without indicating pathology.
Confirmed ovulation proves your body is releasing an egg. It can't assess egg quality, sperm parameters, fertilization capability, or implantation success. Those factors only become visible through conception or medical testing.
Fecundability — monthly conception probability — is heterogeneous across couples3. One review notes that even after 12 unsuccessful cycles, untreated live birth rates in subfertile couples reach nearly 55% over the next 36 months1.
Longer time-to-pregnancy doesn't always indicate something is broken. Sometimes it reflects being on the lower end of the normal distribution. Two couples can both be "fertile" in the clinical sense, but one conceives in month 2 and the other in month 10 because their baseline odds differ naturally.
One review concluded that most pregnancies occur in the first six cycles of fertility-focused intercourse, after which serious subfertility must be assumed in about every second couple, and that a basic infertility work-up after six unsuccessful cycles can identify couples with significant problems1. You're in the zone where both are possible.
Sokkai tracks cycle changes over time, which makes patterns like this easier to spot and bring to a clinician. See how Sokkai works →
Infertility evaluation is generally offered after 12 months of trying in women under 35, versus 6 months in women over 354. Your odds are still good — just not as fast as you'd hoped.
If you're 35–40, ACOG advises fertility evaluation after 6 months4. At 8 months, you've already passed that threshold, which means seeing a doctor now is appropriate — not because something is definitely wrong, but because age-related decline means time matters more.
If you're over 40, immediate evaluation is recommended regardless of how long you've been trying.
ACOG recommends fertility evaluation after 12 months for women under 35, after 6 months for women 35–40, and immediate evaluation for women over 40 or those with known risk factors.
Male factor is a cause of infertility in 40-50% of couples4.
Most pregnancies occur within the first six cycles of fertility-focused intercourse; couples with a reasonably good prognosis, such as unexplained infertility, may be encouraged to wait because treatment would not improve their chances1. Most pregnancies occur within the first six cycles with well-timed intercourse; after that, serious subfertility must be assumed in about half of couples still trying, although many of these still conceive without treatment over the next few years1.
There's no harm in seeing a provider if the uncertainty is affecting your mental health. Some doctors will do baseline testing — bloodwork to check ovarian reserve and thyroid function, semen analysis — for reassurance even before 12 months. A basic infertility work-up after six unsuccessful cycles with fertility-focused intercourse can identify couples with significant infertility problems, and couples with a reasonably good prognosis may be encouraged to wait because treatment would not improve their chance of conceiving1.
Red flags that warrant earlier evaluation: irregular cycles, severe menstrual pain, known male fertility issues, or any symptoms suggesting a reproductive health condition.
One review notes that most pregnancies occur within the first six cycles of well-timed intercourse (about 80%), and that after 12 unsuccessful cycles untreated couples still have substantial chances of conceiving in later years1.
We also don't know what percentage of couples who conceive naturally between months 8–12 go on to have underlying conditions detected later, such as in subsequent pregnancies. Does conceiving in month 10 mean you were always fine, or does it sometimes mask issues that surface with the next attempt? The data doesn't tell us.
The psychological experience of this limbo period — "probably fine but maybe not" — is rarely addressed in fertility research.
Every two weeks · English
Same rhythm, same standards, in your inbox.
Check your inbox. We just sent a confirmation link — one click and you're on the list.
Sokkai learns your pattern over time and gives you a clearer picture of what your cycle is doing — even when it refuses to be predictable. Join the waitlist for early access.
Join the Sokkai waitlist