I know progesterone is pulsatile so swings in PdG are to be expected somewhat… but I find my extreme swings in the luteal phase pretty anxiety inducing. 

As background.. I just turned 38 and had my first at 35. We got pregnant on our first try with him. We didn’t start trying again until October 2025 and also got pregnant first try, but unfortunately it ended in miscarriage at 7 weeks. Since then, we’ve tried for 7 cycles (this will be our 8th cycle trying) and nothing. We had to take 3 cycles off for various reasons. 

I have confirmed ovulation each cycle, and my cycles are pretty textbook in terms of length. I have a clear LH surge, my FSH isn’t elevated, E3G seems normal. I’ve started to grow concerned and look at possible underlying issues. Did comprehensive bloodwork in through Function in June and found I was pretty low on ferritin (28) and vitamin D, so I’ve been addressing that with supplements ever since. Otherwise everything was excellent including the full thyroid panel. AMH was 2.15, which is good. Did an HSG on CD 7 this cycle and both tubes were totally clear. Husband’s semen analysis was good too (though it didn’t include cell dna fragmentation). My OBGYN prescribed me 200 mg of Prometrium vaginally starting after ovulation through the end of each cycle, so I’ve been doing that the last 2 cycles. 

Basically, I’m at a loss. The only thing I can think of (aside from bad luck, lots of bad eggs or possibly my husbands sperm cell dna being highly fragmented) is the wild ride my PdG takes in the luteal phase. I’m wondering if I’m overthinking that point.

As with my other cycles, it has spiked multiple times this luteal phase - confirming ovulation. But as the chart reflects, it is really up and down. Today at CD 21 with FMU, it was at 4.8, and then at 1pm after lunch and plenty of water, it was up at almost 14. One day it will be at 5 and the next day 11. Per Mira, the Prometrium shouldn’t impact the readings because it is absorbed vaginally and doesn’t go through the same metabolic process as my natural progesterone, so these big fluctuations are my own… and they are consistent with what happened in cycles before I started Prometrium too.

Am I tripping or does anyone else think the PdG measurements in my luteal phase may be cause for concern? 

Is my wild PdG bad sign?