Really unsure of my sexuality.

Hi I'm a 17 year old girl and a bit unsure about weather I am bi sexual or maybe a lesbian. I am a virgin although I have had sexual experiences with guys. There was one occasion when me and a girl I was friends with kissed ( we were very young, not so sure why it occurred ). That was the only time anything happened with a girl though. I used to wander about my sexuality when I was 13-14 but Iv not really thought a lot of it since then up to now. I'm very fussy with guys and the last one was a bad experience with someone I didn't really like. I just find it extremely hard to find guys I like and am comfortable with. I don't really think I could be a lesbian because I look at some guys and find them attractive etc but I think I'm very likely bi. I was thinking about it and I think that there are deffo girls I know who if they were to come on to me I wouldn't resist. And I definately look at girls and find them attractive. I don't know, I'm very confused :S anyone feel similar? Xx