The privates form at 12 weeks and before. At 14 weeks you can tell the gender if the baby isn't moving too much and you have a good angle or view.
I found out at 17w & 5d :) 16w is when the private parts start to form.
My doctor told me i can find out at 16 weeks.
I would've found out at 16 weeks, but she wasn't being a good girl, I found out at 20 weeks. But its not always accurate at 16.
They usually cannot find out the gender until you're at least 18 weeks. But you could always ask your doctor, doesn't hurt to see right!!