I have chemically analyzed finaplix-H on at least two occasions. Only trenbolone acetate (and methyl cellulose binder) was present. I checked by TLC and 1HNMR. THERE IS NO ESTROGEN IN COMMERCIAL FINAPLIX-H.
Fina doesn't aromatize and form estrogen by metabolism so that isn't a possibility either.
As Sigmund stated above, it is plausible that trenbolone itself could be mistaken for estrogen in some types of tests. Remember, trenbolone is not a naturally occuring hormone in humans and developers of an estrogen test would have no incentive or reason to develop a test capable of telling the two hormones apart.
Try this: Assuming that your fina pellets are yellow (not white) and came in a belt (rather than a cylindrical container), have another saliva test bu this time put a little crushed up fina pellet and a little water on the test trip. If that comes back as positive for estrogen, than the hypothesis above is proven.
-Spidey