OMG! So could you get an air embolism when you're not pregnant??
Yep, although it is very, very rare both when not pregnant and when pregnant.
The main worry is the air being forced into your vagina. It would need to be forceful, about the same amount as a spa jet would put out, or the equivalent of blowing up a balloon. Something little like a breath etc is fine as it isn't forcing air inside. Obviously this all becomes a little more worrying when pregnant as it can affect the baby also.