Firstly, congratulations!!!!! So far, so good!! My doctor isn't worried at all, she did a whole batallion of blood and urine tests to check that my nutrient and Vitamin levels were ok, and then prescribed me a whole list of prenatal Vitamins to make sure my levels stay right.
My doctor has experience with pregnancy post sleeve as she and my surgeon are at the same hospital, so I am really lucky! The only thing she said was that post sleeve babies tend to be smaller.
On a personal side, I am almost 11 weeks pregnant and yet to have morning sickness ( don't know if it's got anything to do with the sleeve, but I am not complaining)
Again, congratulations, relax and enjoy the pregnancy and drink lots and lots of water!!!