Hi Tish,
I have just done a quick "google" and had a read of some of the studies done.
hmm, rather interesting, I dont know any more than you but I have been having the most horrendous PMS lately, almost homicidal/suicidal ....I kid you not. then I get down, reallly down.
I am still BFing almost 16 months, will be interesting if anyone else has anything to add.
Also my libido has been MIA since 3 months after DS birth.