the only way to get an accurate baby gender prediction is via a medical test done. An amniocentesis or chorionic villus sampling test will be able to accurately predict the gender of your baby. Doctors will not perform these invasive tests just for the purpose of baby gender prediction. Ultrasounds can provide an semi-accurate baby gender prediction as well, but wrong gender predictions are made regularly
A friend of mine bought 2 and 1 said she was having a girl and the second said a boy. I wouldn't trust them. Wait till your scan when you get a definite answer.