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クロミッド・レトロゾール・排卵誘発注射計算機

Calculate your personalized medicated cycle schedule: pill days, follicular scan windows, 36-hour trigger shot ovulation clock, and timed intercourse protocol.

Quick Summary: Medicated Ovulation Kinetics

Clomid (clomiphene) and Letrozole (femara) stimulate follicular development when taken on Cycle Days 3–7 or 5–9. Ovulation occurs 5 to 10 days after the last pill, or precisely 36 to 40 hours after an hCG trigger shot (Ovidrel/Pregnyl) is administered.

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エビデンスに基づく計算モデル • 監査日: 2026年10月

検証機関: Free Ovulation Tracker 臨床研究および計算方法論チーム

主要引用文献基準: Wilcox et al. (NEJM, 1995 & 1999) • ACOG 実践ガイドライン • WHO 生殖医療基準

プライバシー設計: 100%クライアント側ブラウザ実行(サーバー保存ゼロ)

Medicated Ovulation & Trigger Shot Timeline Calculator

Precision clinical timelines for Clomid, Letrozole (Femara), and Ovidrel/Pregnyl timed intercourse (TIC) & IUI protocols.

Medication Window (CD3–CD7)2026年10月26日(月) – 2026年10月30日(金)Follow your prescribing physician's exact dosing schedule (commonly taken at a consistent hour daily).
Follicular Ultrasound Scan WindowCD10–CD12 (2026年11月2日(月))Transvaginal sonogram to measure lead follicle diameter (target ≥18–20mm before trigger) and endometrial lining thickness (≥7mm).
Predicted Ovulation Window2026年11月3日(火) – 2026年11月7日(土)Typically 5–10 days following last Clomid tablet, or 4–8 days following last Letrozole tablet.
Prescription Supervision Notice

Clomiphene citrate, Letrozole, and hCG trigger shots are prescription medications requiring direct OB-GYN or Reproductive Endocrinologist ultrasound monitoring. Seek prompt medical attention if you experience severe pelvic bloating, rapid weight gain, nausea, or shortness of breath (signs of Ovarian Hyperstimulation Syndrome / OHSS).

Clinical Reproductive Pharmacology: Letrozole (Femara) — Days 3 to 7 (First-Line for PCOS)

Letrozole temporarily suppresses estrogen synthesis without depleting estrogen receptors in the cervix or endometrium. It is the gold standard for PCOS (Legro et al., NEJM), resulting in thicker endometrial lining and higher live birth rates.

The "Testing Out the Trigger" Protocol

Ovidrel (choriogonadotropin alfa 250 mcg) introduces approximately 300–500 mIU/mL of exogenous hCG into your circulation. Because hCG has a biological elimination half-life of 29–36 hours, it takes 10 to 14 full days to clear below the 10–25 mIU/mL threshold of home pregnancy tests. If you test daily starting at 7 DPO, the test line will lighten until almost invisible (negative), then darken again if endogenous pregnancy hCG takes over.

Track Unmedicated Natural Cycles Between Treatment Rounds

Between medicated cycles or when taking a rest month, monitor your natural baseline fertile window with our free online ovulation tracker.

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Clinical Methodology

Mechanism of Action: Clomiphene vs. Letrozole vs. Ovidrel Trigger

Clomiphene citrate functions as a selective estrogen receptor modulator (SERM) that blocks hypothalamic estrogen receptors, triggering an increase in pituitary FSH. Letrozole inhibits aromatase, temporarily lowering estrogen without depleting cervical receptors.

The recombinant hCG trigger shot binds directly to ovarian LH receptors, initiating final meiotic maturation and follicle rupture in a reliable 36 to 40 hour window.

Frequently Asked Questions About Medicated Fertility Cycles

Audited under our Clinical Methodology & Citations.

Why does ovulation happen exactly 36 hours after an hCG trigger shot?
Recombinant hCG binds LH receptors on granulosa cells with high affinity, initiating prostaglandin and collagenase synthesis that systematically breaks down the ovarian wall within 36 to 40 hours.
Can Clomid cause false-positive ovulation predictor kits (OPKs)?
Yes. Clomid stimulates rapid endogenous LH surges while the medication is active. Starting OPKs too early (before CD10) often yields misleading false positives.
What is "testing out the trigger shot"?
Ovidrel contains exogenous hCG that takes 10 to 14 days to metabolize. Taking daily pregnancy tests until negative confirms that any subsequent darkening line represents a true new pregnancy.
What is the ideal timed intercourse schedule with a trigger shot?
Physicians recommend intercourse on the evening of trigger administration, 24 to 36 hours post-trigger, and again the following morning.
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Plan Your Full Menstrual Cycle on Our Free Ovulation Tracker

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📖 Companion Clinical Guide

Read Full Clinical Guide →

Ovulation on Clomid, Letrozole & Ovidrel Trigger Shots: Timing Guide

Groundbreaking physiological analysis based on NEJM, ACOG, and WHO clinical standards.

Explore Guide →

📚 Additional Evidence-Based Reading

Peer-reviewed clinical overviews on menstrual cycle biology, luteal defect, and biomarker testing.