Am I Bi Or Lesbian?

Gemma

Over the past year or so I have realised that I might be falling for girls. Not just any girls but my female best friend. I don’t feel attracted to any girl except my friend. But I’m attracted to boys. I’m not sure if this is a sign that I’m bi, which I think I am, or am I lesbian? I’m 17 and I’m still not sure about my sexuality.