First Doctors visit.

I am going to my first doctors visit. I am 18 and my mom recently found out that I have had sex. She is going with me but I do not feel comfortable talking about my sex life in front of her to the doctor. I would rather not have her in the room with me but she thinks I will not be honest with the doctor. But I think it is too personal for my mom to know everything about my sex life. Either way, wether I have my mom in the room with me or not she is gonna want to know about my sex life and I just know she’s just gonna look at me with disappointment and then I’m going to feel horrible. I do not know what to do and I need advice please.