I got both my genderscans at 18 weeks it seemed like a lifetime passed till I found out that Brice was a Boy and I found out I was pregnant with Hunter at 17 weeks so I didn't have to wait that long. but most doctors do it at 18 weeks I think that 15 weeks you might get a guess but not a definate I would definally wait till 18 weeks at least 20 weeks is even better cause then its definally fully formed and they may be able to see easier. Goodluck hun. what are you hoping for???