Being checked for STDs

Last May , I was sexually assaulted. It turned my world upside down. I am 16 and never told my parents. It may seem weird to post this on here but i have no one to talk too. Having an STD hasn’t ever crossed my mind because i have never had symptoms. My friend got clamydia a month ago, and said she knew she had something because she had symptoms. It got me thinking about how i had never been checked and have currently been with my boyfriend for 7 months. I did research and saw that most people don’t even have symptoms. so last week i made an appointment with a clinic and my friend it taking me. the appointment is this week. and i am terrified. like i am so scared i’m going to have something. my parents don’t have to be present because in my state, it is strictly confidential to do the legal age of consent. but if i do have something how will i get treatment. my boyfriend knows and has been supportive. but what if i gave him something ? i’m so scared. and i don’t know what to expect at the appointment. please i just need advice.