I know that during pregnancy you do excrete pregnancy hormones through the milk (fun fact from Adventures In Tandem Nursing), but I don't know if it shows up right away. Also, I don't think there are ANY tests to test for it.
Some women say that their talking nursers will tell them that their milk tastes funny during AF. Others note a difference before or soon after the mama finds out she's pregnant. But, that may not be the actual pregnancy hormones the child notices, but rather changes in milk composition/flavor. (Adventures In Tandem Nursing told me about that, too. It's a good book. The scientific chapt well worth the read just for any nursing buff.)
Best wishes. Hope your milk and your urine are coming up positive real soon!
I always wished your pee would change colors if you were pregnant...like it would turn purple or something....or better yet, blue if a girl and green if a girl (pink would look too much like peeing blood).