okay, i am going to be a huge downer here, but i have been having pretty much those same symptoms for the past 3 months and after taking many a hpt i finally (mostly) believe i am not pregnant. for me, i believe it is my fertility starting to return- the hormones causing all my symptoms. that said, my situation does have a few differences from yours so that could be all the difference:
-my son is only 15 months old,
-i haven't even seen a slight line on a test, though i've not taken one out of the trash yet,
-i haven't had a 4 day nursing hiatus,
-and my partner and i had been using condoms (though i did get pregnant while using bc last time),
but i've been extremely nauseous at times, sensitive to smells (my own skin), skin breaking out, very tired, emotional as all get out, sore breasts, decreased milk supply....
i *hope* you are pregnant, but i just wanted to let you know my story too.
even if you aren't pregnant at least it's good news that something is going on in there, huh?!
keep us posted!