We found out at 13w because we had the Harmony blood test done to look for chromosomal abnormalities and sex is one of the things they identify. We lost our first two pregnancies which is why we had the test done. From a scan though the earliest with an extremely good sonographer is 15-16w. Most of the time I think people find out around 18-20 weeks since it is much more clear around that time.
they can usually tell you the sex of your baby at your 20 week anatomy scan, as long as baby cooperates. they usually don't tell you until near the end though, as this is not the point of an a/s. it's to make sure baby is developing properly.
Re: Question
https://lmgtfy.com/?q=When+do+you+they+tell+you+the+sex+of+the+baby+?+
https://lmgtfy.com/?q=What+is+the+actual+purpose+of+an+anatomy+scan?
BFP #2: 10/8/14, EDD: 6/22/15, MC: 11/13/14 (D&C)