I know that everyone is different but mine did. It was a tough decision to have to supplement with formula but I did. I can't remember where I read what happens as your progress in your PG but when she weaned was about the time the milk would start getting ready for the one I was carrying (if that makes sense).
What your milk does during your pregnancy is really variable. There was a distinct difference for me between pregnancies #2 & 3, even. My milk never obviously turned to colostrum this last time around (although I'm sure it did). My supply drops, but some women have their milk disappear completely, & I've heard the theory that it changes taste too.
Cograts Rakkoon!!!! It's very exciting isn't it? I just found out this week that I am pregnant too!! This is my first and I am in heaven! What # is this for you? Well, . I hope you have a healthy happy pregnancy!!