Someone is accusing me of ?

ok so about a month ago the day before thanksgiving so i think october 13th, (everything i say here im gonna say to the cops depending if i should) but anwyays, i got a gram of weed and a girl named tiffany asked if i could walk to her place and smoke her up, and i didnt think she livied as far as she did, but anyways i ended up getting there and we smoked up then we went inside, and later on we went downstairs and she asked me if i wanted to spoon and honestly (im 17) but i didnt know what spooning ment, she told me it ment cuddling, so i said okay i wet over and we did, then she kissed me and then her exact words when she got turned on were "f %&@ me" so we did and it was mutual,then afterwards , we hung out alot, then she asked me to come over again but she had a bf at this time, so i said no, then just today im at school and find out shes telling everybody and people outside of school, that i had drugged her up and rapped her !! i am 100 percent against but anyways, shes saying it, i asked my uncle what i should do about it cuz lots of people are coming up to me asking and saying she swore i d her, (and shes the type of person that can convince herself something that isnt true, cuz when i asked her she even told me "me raping her was true :SSSS" but anyways, my uncle tells me i should go to the police, and im thinking about it, but what could happen if i go to the police? am i able to charge her for slander by telling people untrue things about me and none other then and is nothing to mess around with and its not funny in anyway, so im wondering what could happen if i go to the police, because i dont appreciate everyone coming up pissed off at me for raping someone when i never did it, and honestly i would like to charge her, cuz my brother was d when he was younger and im against it 100 % and it just, idunno even how to explain how much it discusts me, anyways some help would be great , and thanks everyone for your answers