Hi, the standard seems to be 20 weeks when an anatomy scan is done. Some go a little earlier, I've met a few women who were told baby's sex at 16 weeks.
Morning, you can have a blood test called Harmony Blood Test and it gives you accurate 99.9% risk for downs and also give you 100% gender confirmation. It had to be done privately and is avaliable from 10 weeks x
Re: gender scan