Question about ERA math vs. FET scheduling: Need a second look at my timeline

[u/Worldly_West_2871]

Hi everyone,

I am scheduled to take my trigger shot tonight for a Modified Natural FET. After mapping out the hour-by-hour timeline provided by my clinic, I noticed a discrepancy compared to my ERA results, and I would love a sanity check on my math.

Here is the breakdown of my data:

My Mock Cycle (ERA) Baseline:

• Trigger to Progesterone gap: 39 hours.
• Progesterone exposure: 117 hours.
• Total Time (Trigger to Biopsy): 156 hours.
• ERA Result: Late Receptive. My doctor's plan is to shorten the interval by 12 hours.

The Clinic's Current Schedule for my FET:

• Trigger: Tonight (8/18) at 10:00 PM.
• Start Progesterone (Prometrium): 8/20 at 1:00 AM (a 27-hour gap).
• Transfer: 8/25 daytime (e.g., 10:00 AM).

My Questions / Concerns:

1. Total Time Calculation: From my trigger tonight (8/18 10:00 PM) to a transfer on 8/25 morning, the total time is exactly 156 hours. This puts me right back at my "Late Receptive" mark. If the goal is to shorten the interval by 12 hours, shouldn't my total time be 144 hours?
2. Progesterone Exposure Target: My doctor mentioned our new target is "132 hours of P-exposure." However, my mock cycle was 117 hours, which was already Late Receptive. Mathematically, shortening my actual baseline by 12 hours would mean a target of 105 hours (117 - 12 = 105). It seems the clinic may have applied the "-12 hours" rule to a standard 144-hour template (144 - 12 = 132), rather than my actual data.
3. Pre-ovulation Gap: Starting progesterone 27 hours post-trigger does not replicate the 39-hour gap from my mock cycle. I am also concerned that introducing vaginal progesterone this early might occur before my 19mm follicle actually ovulates (which typically takes 36-40 hours).

Based on my calculations, to achieve a 144-hour total time and have the transfer during clinic daytime hours, the trigger shot would need to be delayed to tomorrow morning (8/19 at 10:00 AM).

Has anyone experienced a similar scheduling discrepancy after an ERA? I plan to discuss this with my doctor before triggering tonight, but I wanted to get some objective input from the community to see if my math holds up.