Am I able to do STD test, so my parents won't be aware of it?

Hello, my name is Olivia, I am 17 years old and I wonder if I have an infection, however I'm not sure. I just have weird rash in my genital area. I had a few one night stands, but cause I started worrying about my health I stopped doing it, and started dating one boy. I didn't know whether he had infection, and I never asked him. Now as I have this pain, I think he might be. I would like to to check myself for STDs, but I'm so scared. I know there is home STD testing like Edit (Moderator): Link removed, but I've never done it. I really would like to be healthy like everybody that's why I would like to do this test. Do you know how I can perform it, so my mom and dad won't see I performed it. And do you know how much does it cost?