As the poster above said, as long as you're not instructed to not have any kind of sexual activity, and the vibrator is clean (cleaned before and after use) it's safe to use them.
I was wondering if it had to do with stimulating organisms and somehow leafing to contractions during pregnancy, just couldn't figure out any other connection (other than normal hygiene).
As long as your vibrator is clean and you are having a normal pregnancy (not high risk) it is fine. But u can always ask your dr. I just did some research cuz i have been curious too :)
I was wondering the same thing I used them in the begining, just haven't since,