Timing of Ovulation Based on Your Hormone Data
Based on your LH surge pattern and symptoms, you most likely ovulated in the early morning hours of CD14 (approximately 12-24 hours after your peak LH of 45 at 7:30pm on CD14), making the egg viable until approximately the evening of CD15.
Understanding Your LH Surge Pattern
Your LH surge began on CD13 and peaked at 45 on CD14 at 7:30pm. Ovulation occurs 8-20 hours after the LH peak, or 28-36 hours after the beginning of the LH rise 1. Given that your LH started rising on CD13 (from 12.3 to 26.7), and peaked on CD14 evening, ovulation most likely occurred in the early morning hours of CD15 (approximately 12-20 hours after your peak) 1.
Key Indicators Supporting This Timing:
- The pulling, achy cramps at 2am on CD15 were likely ovulation pain (mittelschmerz), occurring as the follicle ruptured and released the egg 1
- Your LH dropped significantly by CD15 morning (from 45 to 18.6), which is consistent with post-ovulation hormone changes 2
- EWCM on CD14 indicates peak fertility immediately before ovulation 1
- The rapid decline in LH after the peak (45 → 22 → 12.1 within hours on CD14 evening) suggests the surge was completing and ovulation was imminent 2
Egg Viability Window
The egg remains viable for approximately 12-24 hours after ovulation 1. Since ovulation likely occurred in the early morning of CD15 (around 2am based on your cramping), the egg would have been viable until approximately evening of CD15 or early morning CD16 at the latest.
Effect of Letrozole on Your Cycle
Letrozole (an aromatase inhibitor) affects your hormone patterns in specific ways 3, 4:
- Your rising E1G levels (176.2 → 215.1 → 258.6) indicate follicle development, though letrozole typically results in lower estrogen levels than standard ovulation induction 3
- Letrozole may shorten the luteal phase compared to other fertility treatments, which is why your LH surge pattern and timing are the most reliable indicators 4
- Your PDG (progesterone metabolite) remained low (1.6 → 1.5 → 1.1) through ovulation, which is expected, as progesterone rises significantly only after ovulation occurs 5
Clinical Interpretation of Your Hormone Pattern
Your LH surge showed multiple peaks and extended duration (CD13-CD15), which is actually within the normal range of variation 2. Research shows that:
- LH surges lasting >3 days are associated with normal ovulation but may correlate with slightly lower progesterone in early luteal phase 2
- The configuration of your surge (rising from 12.3 to peak 45, then declining) follows the expected pattern for ovulation 2
- Your symptoms (EWCM, cramping, nipple sensitivity, flushed cheeks) all correlate with the periovulatory period and rising estrogen 1
Confirming Ovulation Occurred
To confirm ovulation retrospectively, you should:
- Check PDG levels 7 days after suspected ovulation (around CD21-22 in your case). A level ≥5 µg/ml in urine or progesterone ≥5 ng/ml in serum confirms ovulation 5
- Your basal body temperature should show a sustained rise starting around CD15-16 if ovulation occurred 1
Important Caveats
- Letrozole can affect the typical 28-day cycle assumptions, so timing based on LH surge and symptoms is more reliable than calendar days 4, 6
- The exact moment of ovulation cannot be determined without ultrasound visualization of follicle rupture, but the 8-20 hour window after LH peak is the most accurate clinical estimate 1
- Sperm can survive 3-5 days in fertile cervical mucus, so intercourse from CD11-CD15 would have been within the fertile window 3