You'll know the gender of your baby as they grow up, when they tell you.
Usually you can find out the sex at your anatomy scan at around 20 weeks. Sex organs don't start developing until 14-16 weeks, so anything before that is typically innacurate.
Seriously, there's a post 5 lines below this one titled "How many weeks can you find out the gender?" Has internet etiquette gone the way of real-life etiquette? Scan a board to see if your question has been answered already.
Re: When Will I know the gender for my baby I'm 14 wks