When should I start taking progesterone to time my menstrual cycle for a fertility assessment appointment on September 30, 2025, to coincide with days 2-4 of my cycle?

Timing Progesterone for Fertility Assessment Appointment

You should start taking progesterone 14 days before your desired menstrual cycle start date, which would be September 26,2025, to ensure your September 30,2025 appointment falls on days 2-4 of your cycle.

Understanding the Timing Process

When taking progesterone to induce a menstrual cycle for fertility testing, the timing is critical. Here's why this recommendation works:

1. Progesterone withdrawal bleeding:

   • Menstrual bleeding typically begins 2-4 days after stopping progesterone therapy 1
   • The FDA-approved dosing for secondary amenorrhea is 400 mg daily at bedtime for 10 days 1

2. Calculating backward from your appointment:

   • Your appointment is September 30,2025
   • You need this to be days 2-4 of your cycle
   • This means your period should start between September 27-29,2025
   • Working backward: Take progesterone for 10 days (September 16-26), then stop

Detailed Schedule

• September 16-26,2025: Take progesterone 400 mg orally at bedtime for 10 days
• September 27-29,2025: Expect menstrual bleeding to begin within 2-4 days after stopping progesterone
• September 30,2025: Fertility appointment (should fall on days 2-4 of your cycle)

Administration Tips

• Take progesterone with a glass of water while standing 1
• Take it at bedtime to minimize side effects like drowsiness
• Be consistent with timing each day

Important Considerations

• Monitoring: If your period doesn't start within 4 days after stopping progesterone, contact your fertility specialist as the timing for your appointment may need adjustment
• Variability: Individual response to progesterone can vary, and withdrawal bleeding might start slightly earlier or later than expected 2
• Documentation: Keep track of when you start and stop the medication, and when bleeding begins, as this information will be valuable for your fertility specialist

Potential Pitfalls

• Delayed response: Some women may experience a delayed withdrawal bleed after progesterone discontinuation
• Early response: Some may start bleeding before completing the full 10-day course
• No response: If you don't experience withdrawal bleeding, this itself is diagnostic information for your fertility specialist

This timing approach aligns with standard protocols for inducing menstrual cycles for fertility testing and should position your appointment appropriately within the early follicular phase when baseline hormonal assessments are most informative.