It depends on how intense the place you play is at. My sister in law played up until she was 7months pregnant, However, it was a co-ed pick-up style game and everyone made sure to not spike at her and she stopped diving right away.
Volleyball would be a great workout during the early months of pregnancy.
Stay active. It will keep you and your baby healthy.
However, keep in mind that you need to be extra cautious. No diving, no bumping into each other etc
Utilize calling firsts when hitting the ball.
As your stomach grows I would stop playing for safety reasons but stay active!!! Its good to keep your workouts!!
I would avoid an intense sport like volleyball. I played for a while in school and it could be dangerous if played the way we did. Try to take it easy. Probably not worth the risk.