The typical saliva ferning pattern is seen starting several days before ovulation, during your fertile days. A second estrogen surge and ferning pattern may occur about a week or so after ovulation, towards the end of your cycle. By monitoring cycle length, and keeping daily results, the second surge should not be confounded with the estrogen surge preceding ovulation. Also, as different women produce differing levels of estrogen, ferning patterns may vary a bit in appearance and duration.