Are soy products safe to eat during pregnancy?
Probably. I base this on the fact that the amount of estrogen in your system by the end of pregnancy is a thousand times more than what you have before pregnancy! Soy is a source of estrogen, but it's not very potent. This is evident by how it pales in comparison for relieving menopausal hot lashes as compared to prescription hormonal replacement.
Since a pregnancy is dumping an unbelievable amount of estrogen into a woman's system already, I would think that any extra estrogen from soy sources would get lost in the shuffle.
It won't do much to help any gas problems you may have during pregnancy, though.