hack to change your period due date

So basically my friend told me of this phenomenon that im surprised more people arent talking about. Basically if you have sex or insert anything at all wether penis finger or vibrator into your vagina it will push back your period or make it come sooner.

My friend was explaining to me that whenever she had somewhere to go and she knew her period was coming she would simple have sex a couple days before and BUPS! No period! And i ask other friends and they backed up it up.