good age for the gynecologist??

what's a good age to start going to a gynecologist? im 15. i really want to go get checked but im afraid because of my age. i've been having extremely irregular periods, very weird discharge, itching down there, and i want to get checked for stds. the couple times i've had sex i haven't used protection so i want to get checked for some reason. and if i do how do i talk to my mom about it? thanksss