Birth control and parents..

So my mom is putting me on birth control but she thinks it is for my periods but it's actually because I'm sexually active and don't want to get pregnant, I know they have to ask if u have been sexually active and I'm only 15 so my mom will be in the room with me and I have to be honest with them so I can't tell them I have but have her in there cause she will be so disappointed, is there any way I can not tell the doctors and still get good birth control, ugh I'm so confused can u guys help?