OP, Id be wary of making too many conclusions about yourself from just 1-2 cycles of temp charting.
That said, seems there is some interesting research on Vitex. Doesn't seem it hurts and at least one small randomized control trial found some positive effect. Anyone else tried this herb extract? What do have your doctors said?
http://www.aafp.org/afp/2005/0901/p821.html
"In another small RCT26 involving 52 patients with luteal phase defects, women in the active treatment group were found to have reduced prolactin release, normalized luteal phases, improved luteal phase progesterone synthesis, and increased luteal phase estradiol. This study appears to support the use of chasteberry for luteal phase disorders, but the actual effect on fertility was not mentioned. A recent double-blind placebo-controlled pilot study27 of 30 women showed an increasing trend in midluteal phase progesterone level and an increased number of pregnancies in the 15 women who took a nutritional supplement containing chasteberry for five months."
Same study also referenced here:
https://www.ncbi.nlm.nih.gov/books/NBK144218/#!po=8.33333