The only thing I'd worry about is heat from a laptop. I think newer ones may not be so bad? But some of the older ones got pretty hot, and thus they actually even say not to use in your lap period (pregnant or not). But that's just a heat issue due to all those electronics being stuffed into such a small space without adequate circulation.
Because of the heat issue, I generally like to put a laptop on top of a table or at least on top of a board or something so it's not directly on my lap. You can feel your laptop's bottom when running, and if it feels pretty warm, maybe put it on a table when using it.
Mama to Tornado Boy (6/04), The Brute (11/06), and Mischief (05/09)... expecting
in February '15