Timing of Ovulation and Optimal Intercourse Window
Based on your hormone data, you most likely ovulated in the early morning hours of CD15 (approximately 12-36 hours after your LH peak on CD14), making CD13 evening through CD15 morning your optimal fertile window for intercourse.
When Ovulation Occurred
Your LH surge pattern indicates ovulation timing as follows:
- LH surge onset: CD13 at 6:15 PM (LH 26.7) 1
- LH peak: CD14 at 9:30 AM (LH 45.0) 1
- Estimated ovulation: Early morning CD15, approximately 16-32 hours after your LH peak 1
The World Health Organization data demonstrates that ovulation occurs 16.5 hours (median) after the LH peak, with 90% of women ovulating between 8-40 hours after peak 1. Your declining LH values (22.0 at 7:30 PM CD14, then 18.6 on CD15 morning) combined with the absence of cramps on CD15 and continued EWCM strongly suggest ovulation had just occurred 2, 3.
Supporting Evidence from Your Hormone Pattern
Your estrogen (E1g) pattern confirms this timing:
- E1g rise: CD13-14 showing follicular maturation (176.2 → 215.1 → 258.6) 4
- Peak cervical mucus: CD13-14 with "thick sticky gluey stretchy mucus" and EWCM coinciding with LH surge 3
- Progesterone (PdG) baseline: Remained low (1.6 → 1.5 → 1.1), confirming pre-ovulation status through CD15 morning 5
The 2-hour pulling/achy cramps at 2 AM on CD15 likely represented the actual moment of follicular rupture, as ovulation pain typically occurs at or just before follicle rupture 2.
Egg Viability Window
The egg remains viable for only 12-24 hours after ovulation 2. Given your likely ovulation time of early morning CD15, the egg would have been viable until approximately late evening CD15 or early morning CD16 at the absolute latest.
Optimal Timing for Intercourse
For conception, intercourse should occur from CD13 evening through CD15 morning 1, 3:
- Best timing: CD13 evening through CD14 (during LH surge and peak EWCM) 3
- Still effective: CD15 morning (day of ovulation) 2
- Less optimal: CD15 evening or later, as egg viability declines rapidly 2
Sperm can survive 3-5 days in fertile cervical mucus, but the egg survives only 12-24 hours 2. Your maximal cervical mucus scores on CD13-14 coincided perfectly with your urinary LH surge, creating the optimal environment for sperm survival 3.
Critical Timing Considerations
Your hormone monitoring revealed important nuances:
- Rapid LH surge onset: Your LH jumped from 12.3 to 26.7 within 9 hours on CD13, representing a "rapid onset" pattern seen in 43% of women 4
- Spike configuration: Your LH peaked sharply at 45.0 then declined rapidly, consistent with a "spike" pattern (42% of women) rather than biphasic or plateau 4
- Optimal mucus window: Your cervical mucus quality peaked during CD13-14, then would have declined rapidly within 24 hours after LH surge 3
Common Pitfalls to Avoid
Do not rely solely on basal body temperature, as the thermal shift occurs after ovulation and cannot predict the fertile window prospectively 2. Your quantitative hormone monitoring provided far superior real-time information 5.
Do not assume fertility extends beyond CD15 evening in your cycle. While some women have longer viable egg windows, the median is 12-24 hours, and waiting until CD16 or later would likely miss the conception window entirely 2, 1.