for each of these hormones , the initiation of a secretory cycle occured at a different time : on the 10th day after mid-cycle surge for gonadotrophins , on the 3 rd day of menses for estradiol and somewhat later for estrone , on the 8th day of cycle for 17-hydroxyprogesterone and on the day of the lh surge for progesterone .
C0020387
17-hydroxyprogesterone
C0033308
progesterone