Hey godiva, I also saw your reply in the PM forum but I will only answer you here. My breasts are the smallest on day 5-7 of my menstruational cycle and f.ex this cycle they were 1,5 cm smaller then with the lutheal swelling. Are you sure it isn't just lutheal swelling going away?
I have never heard of PM shrinking the breasts. However, I am also estrogen dominent and I used PM for 2 months with no results. I started using the progesterone only pill with PM and I grew 1,5 cm in one month. If you are estrogen dominant, raising estrogen will not do anything for you. Before I started the PM I used PC for a few months but I guess I still didn't balance my hormones enough since I didn't grow.
PC did not grow my breasts and neither did the progesterone only pill alone. However, with PM and POP I did grow. It is not surprising since I know I am estrogen dominant with low estrogen and even lower progesterone. I am having no bad side effects at all.
If you grow on PC alone, you might have estrogen dominance with normal or high levels of estrogen and low progesterone. But the thing is, you could also have normal progesterone levels and high estogen and if that is the case you don't need extra progesterone but to lower your estrogen exess and that is done with weaker phytoestrogens then PM.
Good luck and keep us informed