Kim I have had 2 boys so I know a penis when I see one on u/s and I have to agree with Tanya, thats a boy! Im pretty sure I can see a set of testicles in that pic and that is the best way to tell. Both my boys balls were seen from 13wks, a big mass of grey just under the bottom which you have in your pic.

Good luck with the 3D scan though, I sure hope its still a boy then!