Hi!
A single exposure like that is unlikely to cause any major problems. I ALWAYS recommend notifying your doctor right away, but there is probably not too much that they can do.
If you were my patient, I would do an ultrasound to confirm that everything is alright at this point, and then have a "heart to heart" with you about your job--could you take some time off? or switch to another location for a few weeks? Continued exposure to anesthetics ( such as anesthesiologists have ) has been associated with some risks.
Good luck and congratulations!
Dr B
No need to worry. Do inform your doctor. But also know that anesthetic gas is used in other countries for pregnant women as a pain option during dilivery, known to cause no harm to the baby. America is one of the few countries that doesn't provide that. Long term exposure is not recommended (Like every day).