S.H.
I had round-the-clock nausea during the second week after my son was born. After doing a little research, I had come to the understanding that it was somehow related to lactation. I found some comfort in this online article:
http://www.kellymom.com/bf/concerns/mom/nausea-bf.html
I was surprised that my doctors had never heard of this scenario; however they went ahead and prescribed me an anti-nausea (Reglan did not work and Zofran worked a little). The nausea only lasted a week.
Also, when my son was around 4 months old, I began to have some symptoms that are often associated with pregnancy (occassional dizziness and a metallic taste in my mouth). These have also subsided now that he is 5 months old.