for anyone who might be interested, i found these notes i had taken a while back:
says that vaginal suppository is best route of progesterone supplementation
kliman seems to be all about endometrium receptivity. all this is way above my pay grade! i couldn't really find anything that specifically defined how the gradual supplementation of progesterone works or what the specific protocol is. the most specifics i saw were on the network 54 donor egg board. it sounds like kliman is pretty accessible.
i don't even know the difference between antagonist and agonist protocols, but here is an abstract from kliman that says antagonist protocols may be associated with impaired endometrial receptivity.
his endometrial function test is trademarked and sounds a little... opportunistic possibly? i just don't know. it does sound promising, though.