I have used the saliva ferning tests for about 5 years (mainly as a birth control aide until I was ttc). They can be tricky and give you inconsistent results unless you are using them right. It is best to use first thing in the am and especially before you eat, drink, or brush your teeth - any of this stuff can impact your results. Also, it is best to use saliva from under your tongue and apply it with a finger (I always used my pinky) - you don't want too much or too little saliva (something you have to experiment with). Once I go the hang of it, mine was amazingly accurate and coincided with a digital OPK I got once I was ttc.
Best of luck
Thanks for you advice. I have been using first-thing-in-the-am saliva, but I am going to try the under-the-tongue, apply-with-pinky technique that is successful for you. Congratulations on your pregnancy and best wishes!!!