Progesterone
I just read that Progesterone is in saliva. This big hormone that plays a big role in women's menstrual cycle.

Could this be a chemosensory signal that women have PMS?
Have you ever known a woman was PMS'ing by smelling her?

Another place that Progesterone shows up in is pregnancy. My wife had bad morning sickness (hyperemesis gravidum) and her Progesterone levels were like 100X that of a "normal" pregnant woman (normal, haha). She also had a bad taste in her mouth that lasted throughout the pregnancy. The taste made foods she liked previously, not taste good anymore (especially diet coke).

I know that some 'mones affect my sense of taste, and some foods don't taste like they usually do.

Also with Progesterone, a major chemical in BCP, it can change a girls outlook to what she is looking for. How women will switch almost 180 in what they are looking for in man smells based on if they are on BCP's or not. Seems like Progesterone could be a 180'er. Causing people who are affected by it to look for attributes in a mate that they wouldn't otherwise. Maybe it would only be effective as a internal medicine over long term use, or maybe it could be on a short term pheromone exposure setting. Triggering a switch in personality that would cause a girl who digs you to be disinterested, and vice versa.

This is all speculation, but if Progesterone in saliva increases and decreases with serum levels of Progesterone, It is coming at you every time she exhales. Kindof like Androstenone when those pigs exhale, causing LORDOSIS and getting it on.