i can't orgasm! help!

my boyfriend and i have regular sex but i cant find myself to orgasm. when im alone..rubbing my clit does nothing for me. and when he eats me out..i feel nothing. but i love it when he fingers me..and when it goes in deep with doggystyle... any tips? i would reallyy want to have an orgasm bc it's frustrating after sex, still having that mood of wanting to fuck..