I ordered some progesterone oil from John Lee and it came with a booklet on what to avoid...lavender is just the tip of the iceberg, a LOT of herbs, spices, foods are estrogenic or phytoestrogens.
A lot of progesterone cremes are made with xenoestrogenic ingredients...parabens, cet.
My opinion(for what it's worth) is that it is far more important to avoid xenoestrogens rather than phytoestrogens...unless, of course, you have an estrogen dominance condition that is not budging.
That lavender is a phytoestrogen is eye-opening. Using it daily(in my own skin creme) did not prevent the resolution of FBD. Even so, I'm working on a phytoestrogen(AND xeno, of course) free formulation.