I used this twice and it said boy. I used a intelli gender tests which is much cheaper and I did it at 15 weeks and it said girl. did the vinegar gender test with my urine and results were girl. I'm having a girl :) was told at 15 weeks and verified again at 19 weeks.
hate to tell you but all those kits etc. are kinda bs lol only way to be 100% sure is from a blood test or at an ultrasound :)
The Chinese calendar thing worked for me, said I was having a boy and I am