I’m 18 (f) and my boyfriend is 19, and recently i’ve noticed a strange pain during sex. Sometimes it feels like his penis is pushing my labia inwards of that makes sense? And when he puts me in a certain position on my back it strikes pain at the very top of the entrance to my vagina, but not only inside and not on my clit. It feels like friction and it doesn’t hurt when he’s behind so what could this be?