GYN question PLEASE HELP😊

I'm 17, and I'm on birthcontrol and since it started I always got really bad stomach cramps and back pain which I never had before. I never really made the time to go to the doctor because I just let it go and when I've seen her before she just wrote me the script and I never had an actual visit really just a few questions. Now I have an appointment to change my medicine at the end of July but since the computer says I haven't been there in a while I need to actually visit her, since the last time I saw her, I lost my virginity to my boyfriend. Does it matter if I actually tell her if it's just to change medicine and I know that I don't have any STIs? Or should I just tell her? And would she be allowed to tell either of my parents that I'm sexually active? Or does that fall under doctor patient confidentiality, even though I'm 17?