Is it normal that i am straight; but lesbians turn me on in porn?

Is it normal that i am 100% straight, well at least i think i am, i haven't had sex with a boy or a girl (i am a girl by the way) but i've done stuff with a boy, i enjoyed it..but i'm curious to whether i'm bi-sexual or not..when i watch porn and pleasure myself, man and women and lesbian porn turn me on.. is this normal?