I've started experiencing the same thing as of about two days ago. My stomach is so hard between the bottom of my breasts to just below my bellybutton that I can barely bend over to do stuff like pick something off the floor or tie my shoes.
But from the top of my pubic line to about three quarters up before my belly button, my stomach is softer (where the baby is located).
i am 12weeks and my stomach from the bottom of my breasts to the bottom is all rock hard..this is my 4th pregnancy and i had this with my other kids too..its normal
I am not sure if it is normal or not since this is my first....but, I'm in my 11th week and I have the same type of thing. I am flat from the breast line to my belly button (rib cage area) and then I fluctuate from the belly button down depending on what I ate or drank the day before. Somedays I am more round and other days I am flabby.