sneak peek accuracy

Katie • Pregnant with our first after being told by a fertility specialist that I hadn`t been ovulating/would need IUI and potentially IVF in order to have a child.
Has anyone taken the sneak peek sex reveal test and had the results be wrong? I ordered it all excited and am very, very good at spotting scams so if this is one, their marketing is brilliant. I am just worried I may have wasted money but the website is SO convinving, and the money back guarantee, but it's a little odd that it's only after the baby is born and not after sex is revealed in an ultrasound.
*EDIT: please only comment if you have taken the test and the results were either right or wrong.