I am 15 in one month and have never had a boyfriend, why?

i am a normal girl who is normally clever and normally pretty, i am nice to people but when it comes to boys i sometimes feel like i can't be myself, all my friends are and have been girls i want a boyfriend and have never met the right guy hu likes me n i like back. what can i do? is it normal for me not to have a boyfriend yet? why have i never had more then 2 guys admitting they are attracted to me? how do i flirt?