Birth control

Ok so me and my mom scheduled an appointment to get the 5 year birth control the mireana and when I got there I just decided to get the pill. It's been 2 months now and my mom never order my pills. I want to be on birth control cuz me and my bf have sex every other week and I'm tired of a condom and I used to let him pull out but made him not do it anymore cuz I had a pregnancy scare. How do I tell my mom about me getting on birth control without her thinking something is up or that I'm having sex ?