Fern test [Cycle 5]

Hi Everyone,

This is our 5th cycle ttc and DH and I have decided to try something new to improve our timing: we are looking at my saliva under a microscope. As O-day approaches we hope to see fern structures, which should appear as a result of increased estrogen. The peak in estrogen, identified by the appearance of the most clear fern structures, should precede the time of O by 1-2 days. Here are some samples. Note that we didn't use consistent microscope settings until cd 12, as we were learning what to look for and how best to find it.

cd 6:

cd 7:

cd 8:

cd 9:

cd 10:

cd 11:

cd 12 (night of O according to temps): Full ferns! - indicates O tomorrow or next day

cd 13 (O-day (also suggested by temps)):

cd 14 (1 dpo):

cd 15 (2 dpo):

cd 16 (3 dpo):

cd 17 (4 dpo):

cd 18 (5 dpo):

cd 19 (6 dpo):

cd 20 (7 dpo):

cd 21 (8 dpo):

cd 22 (9 dpo):

cd 23 (10 dpo):

cd 24 (11 dpo):

cd 25 (12 dpo):

cd 26 (13 dpo):

cd 27 (14 dpo):

cd 28 (15 dpo) af arrives. cd 1 of next cycle:


DH's saliva below serves as a control:


Here is my bbt chart from fertilityfriend.com for this cycle:


Fertility Friend allows for input of fern data to help identify O-day and using this together with the temperature data their O-day postdiction was cd 13. One interpretation is that I ovulated in the early morning on cd 13, given the clear fern pattern observed in the evening on cd 12, the low temp and watery cm on the morning of cd 13, subsequent disappearance of the ferns on the evening of cd 13, and the elevated temps of the next few days. However, since af arrived one day later than usual and my bbt went up very slowly after cd 13, it is possible that I O'd cd 14. Overall the fern test appears to be useful, suggesting that my oestrogen peaks 1-2 days before O-day.

In addition I have noticed that the stress I ordinarily feel after O, wondering if we conceived or not, was reduced this cycle. The gradual decline in the fern pattern after around 7 dpo hinted that this might not be our lucky cycle, reducing the 2 week wait, to a little over a 1 week wait. Fx for the next cycle.