mom issues

My mom has recently confronted me because of my relationship with my boyfriend, and has been very aggressive in the way she asks me about the things we've done. She doesn't trust me anymore and contradicts herself a lot, saying there's nothing wrong with experimenting but also telling me I'm going to fuck up my life. She's taking me to the gynecologist tomorrow for my first check up and I wanted to know what's it like. I've just gone for normal checks. Also if someone can give me some advice on how I can discuss my issues with her without fighting and gain her trust back :(