Help me please

I just turned 18 and i still live with my mom and I'm 26 weeks pregnant. She knows I'm depressed and wants me to talk to my doctor about it in 2 weeks at my next appointment. Well, i honestly can't do it any longer so I'm making an appointment for tomorrow. I want her to go with me. She seems understanding about my depression but she does get mad easily and doesn't want me to stress her out. So how to tell her I, 1. Made an appointment? And 2. Want her to go with me to it?