We had one at 23w and 29w - the 23w was supposedly 'a bit too early' but it was amazing and sooo much better than the 29w one. We couldn't see anything at all on it! I had to go back 6 times (yes 6!) because she wouldn't move and was too far into the pelvis.
https://fbcdn-sphotos-f-a.akamaihd.net/hphotos-ak-xap1/v/t1.0-9/1907895_10100143121248441_6570439535263194003_n.jpg?oh=677c4c5600bc05b440304290066c167a&oe=557422E8&__gda__=1438043601_da0e9f7d2d598c8b43af6c8a99092c74
Here is our 23w one (it says 24 because I said she was a little further on to get an earlier scan as we were going away the next day for 2 weeks and I was desperate to see her before we went!)
I knew she was a girl and I think she has a girly face - but that must be subconcious. I really don't think you'd be able to tell and we never saw her 'bits'.
Aw love the pictures!! I'm leaning more towards doing it.. And just praying I end up team yellow at the end, lol!