I don't believe any of those things work. When they do its just coincidence. Sometimes you can tell gender at 13 weeks, but most likely you will find out between 18-22 weeks. I know it's hard to wait, but it will be here before you know!
I did it and it was wrong im having a boy and it was coming out as a girl i didnt it a couple times and always said girl but no baby boy my doc told me at 16 weeks and was confermed at 23 weeks and im now 34 weeks and forsure still a boy