They can indeed tell the sex of a baby from a blood test but it’s usually from 10 weeks at the earliest, there has to be enough fetal dna in the mothers blood and it usually doesn’t start circulating until 10 weeks, when you get NIPT testing done they will also tell you the sex but won’t do it until you are ten weeks plus so I wouldn’t trust anything taken before ten weeks,if you’ve had yours done at 11 weeks it should be accurate but I’ve heard lots about those sneak peek results being inaccurate as they are not a medical diagnosis lab they are more a ‘just for fun’type thing so I don’t think their methods are the most reliable