How did you tell your family??

I just found out I’m pregnant and I’m 15... The only person I’m nervous about telling is my mom... Because I have disappointed her so much. I want to talk to her face to face about this but I don’t wanna see the sheer look of disappointment on her face😔 So I thought I’d write her a letter but, that seems to I don’t know standoffish? I don’t want to make it seem like I have no remorse for getting pregnant or even having sex because I really really do but I just don’t know the best way to tell her... Any suggestions?