I'm lesbian or bi?

I need some advice from you all. I don't know if I'm lesbian or bisexual. I've taken a bunch of those stupid online quizzes that never tell me anything, and they've always told me I'm bi. I've never thought about a guy in an intimate way, I've only explicitly imagined girls. I've been with both girls and guys. Could it be that I'm only romantically attracted to guys? And to girls in both ways? Sorry for my English, it's not my first language. Anyway, for now I'm bi/ace.