most of the info (if not all) i've found is on pregnant women, as it isn't normal to have hormone fluctuations like you do when you are using exogenous hormones.
but, the hormone imblance is what it is.
'Estrogen promotes prolactin secretion but inhibits its action on the breast.'
it seems progesterone also inhibits prolactins action on the breast as well, if you cared.
once estrogen is lowered, and progestin is lowered, then the elevated prolactin can do it's work.
if all your hormones are in balance, then your fine.