u/Inside-Dragonfruit30

So I live in a religious country where people still very much believe that bleeding on your first time is a sign of virginity, including doctors themselves that pretend that they can check a woman's vagina and be able to determine whether she's a virgin or not... So I know that is stupid and that in no way the hymen being intact is a sign of virginity but my question is, how do these people that pretend they do base their conclusion on ?

P.S. asking because my safety is at risk