I saw this post and got curious myself so I did some quick research and there really isn't much science behind it. It's more a 50/50 chance, basically a rip off. Some people find it fun for ***** and giggles, but I read a couple stories where the test said boy so they went out and bought a bunch of boy stuff, then at the ultrasound it was a girl! So I guess it could be a fun thing but you shouldn't really count on it.
I've reAd about a lot of false boy results. It would be best to wait especially since your hoping for a boy. You don't want to test, have it say boy, then find out girl.
I took the test & it clearly stated that I was a boy but it was a girl. Those test are jus for fun
Also I got the test for $25 at intelligender.com.
I took it at 10 weeks and it said boy, at my ultrasound at 18+1 found out I was sure enough having a boy. Daddy was happy also seem how we have 2 girls together and he has 2 girls from a past relationship.