I had mine last week at exactly 13 weeks, after they put me back 4 days, I asked but they said it was too early. I've seen on here a few women have been able to find out, but think it depends on how big they are, what position they're in etc etc. A few places won't even try guessing as it can be too early to tell sometimes. Good luck though, hopefully your lo is in the right place for them too see!!x