am i transgender

i am a girl but i always shop in the boys isle for pants and t shirts and fit in with boys better then girls. I have a lot of guyfriends and am thinking of making my current boyfriend into just a guyfriend( by the way it was his idea to be bf and gf). I don't like girls but i think i may be asexual (meaning i don't like guys or girls) or fictionsexual (meaning I like fictional characters). I have also thought of wearing chest binding. I don't know what to do, do you think i am starting to be transgender. if you do, should i continue to be transgender. I feel like i'm stuck between being a girl and transgender. I bring this up because i'm writing a story of a transgender girl wanting to be a boy and it made me thinking am i transgender. please tell me what you think. Oh and one quick thing if i am transgender how do i explain it to my friends and family(i really wonder how my boyfriend would react)
(note: a transgender person is someone born one gender but wants to be another. for example: a boy wants to be girl because he feels better as a girl)