Birth control appt

I’ve been on the pill for 8 weeks, and have to go in for an appt in a couple weeks to talk to the doctor about how Things are going. I’m 15 and don’t know what they’re gonna ask me and my mom will be suspicious if I tell her I want to go alone. Will it affect anything if they ask if I’m having sex and I say no even though I am? What else will they ask me when I’m in there?