Should I talk to her?

So my mom and I have a good relationship and she wants to help me in my life whenever I need her. Well I have recently started dating my good friend (who I met freshman year) and I have now known him for three years. We are already close and we kinda skipped right over the awkward stage. Well I feel safe enough and ready to do start having sex (safely of course) and he feels the same. But my mom doesn’t know. She wants me to tell her when I start being sexually active and stuff so she can make sure to tell my doctor but I don’t want to tell her because I feel like she will judge me and try to not let me. What should I do? If anyone is a mom out there what would you do. Btw I’m 16 about to be 17 and a junior in highschool