Stay away or go for it?

im madly in love with this girl at my school... we talk quite often and i think she likes me back but... shes going out with another boy... im really confused as to go for it and tell her everything or stay clear and wait for her to finish this boy... she knows i like someone and i think she knows its her... she makes blatant hints telling me i should tell her at the prom... but i dont know whether shes telling me to go for it with some other girl or she wants me to confront her and tell her everything... im soo confused because i dont know whether she likes her boyfriend or me.... she once told me she had a crush on someone and didnt know what to do because she was seeing her boyfriend.... is this crush me or someone else... i want to tell her how much i love her but dont want to ruin are friendship.... please help!!!