Hey, does anybody know if you can increase/decrease your chances of having a girl or boy while pregnant?

Nope, its already determined. There isnt anything you can do while you are pregnant, its all up to the mans sperm. There are some studies that show that certain diets can help you concieve a boy or a girl, but you have a 50% chance of either and none of the studies show anything more than a 50% increase of either .