Lesbian, preference for girls or just a phase?

I identify as bisexual. It seems so natural for me to like both sexes, and the idea of being a lesbian seems kind of weird to me as I can imagine being with a guy.
Well I don't know, it's complicated. I have attraction to both sexes, but I go through phases as I think other bisexuals do too. The thing is that I most frequently go through girl phases. I think emotionally I am more attracted to girls maybe, but physically it's pretty much exactly equal. However I am also emotionally attracted to guys, but less.

I don't even know how to explain this because I'm so confused inside my own head. If asked what my sexuality was, I would say bisexual. If asked if I had a preference, I would say no it's pretty equal. However, I go through girl phases a lot more often than boy phases and can imagine being in a relationship with a girl more than with a boy. When I think in my head that I might have a preference for girls or be a lesbian, I then immediately think "no, but boys...".

I guess what I'm trying to say is that if this really was just frequent girl phases, I wouldn't even be posting this, but it's basically a preference for girls but with boys still there in the back of my head for the majority of the time, and every few months a week or couple of weeks where I prefer boys.

Do you think that I can still be equally attracted to both genders but just be going through a really long girl phase? Is this a feeling that's likely to last? It's just that ever since I started really identifying as bisexual, I've thought about girls a lot (since about a year ago).

I'm just going to stop typing now because really all I'm doing is going round in circles. I'm sorry if this makes absolutely no sense.