I don't like being referred to as any female nickname or pronoun and I feel very happy in boy clothes. Could I be a boy or might it just be a phase?
You could be I guess, but there's not a lot of info to go off of. It may just be a phase, you could also be gender fluid, bi-gender, non-binary, there's a long list of possibilities, TransWhat? • Glossary of terms, give it some time and thought, and it'll come to you. Some questions to consider: Do you dislike (parts of) your body? Do you get dysphoria?
Additional information: I've been wanting to be a boy for as long as I can remember. I often have day dreams in which I am a guy. And I fit in a lot better wit boys. As a girl I feel kind of trapped. As for the questions, I do sometimes wish I didn't have female breasts and that I had a penis instead of what I have now. and I've been experiencing some social dysphoria but nothing too major.