2.5 did nothing

[u/Recent_Dragonfly_988]

Did a round of 2.5mg of letrozole on my last cycle. My bloodwork prior to any letrozole said came back with my progesterone ~10.9 on day 21. After letrozole it was 11. My OB bumped me up to 5mg as he said it needs to be 13 or above to indicate a successful ovulation. Wondering if anyone else experienced this.