The headache is a symptom of high estrogen. Adjust your dose, or cycle.
Progesterone stops NBE growth. Rosieli described what yucca and red clover, with hops, did to her figure:
http://www.breastnexus.com/showthread.php?tid=8756&pid=30656#pid30656
Yucca is 100 % phyto-progestin
Red clover is 50/50 phyto-progestin/phyto-estrogen
Hops is 100 % phyto-estrogen