Optimal progesterone for conception

[CCT1991]

Hello,
I recently saw a naturopath to get some hormone testing done. We tested my progesterone and it came back around 9. She recommended me going on progesterone to increase to get ready for healthy conception. However, from the period repair manual I read that progesterone can vary quite a bit every 15 minutes. Should I consider testing again before starting progesterone? 9 seems on the borderline to me (PRM book says 10 or above is optimal).
Thank you!!
Chrissy

[CCT1991]

I should add my cycle has always been 25 days, and I ovulate around days 10-12. I gratefully got pregnant with no issues with my last pregnancy. Since being postpartum my cycle is again 25-26 days, but I struggled with big mood swings and hot flashes after weaning breastfeeding which is why we did the hormone testing! My husband and I hope to TTC in the next 4 months or so.