Okay funny story..
I grabbed a helium balloon today and sucked the helium out of it to make my step sister (who's 3) laugh & after both of us were laughing for a good couple of minutes I went into panic thinking, "Oh shit.. I don't think your suppose to do that while pregnant" & I felt really shitty.
(I googled it, and a one time occurrence that's a small amount won't harm baby boy, thank god.)