Help with girl trouble?

Theres this girl i like but shes my bestfriend. weve dated once but we broke up but i still love her. idk if she loves me or not but i dont want to risk telling her and her not wanting to be friends. before you say 'just ask her all she can say is no'. thats not all she can do. i dont want to lose her as a friend and im afraid that if i tell her i will.