HELP 😭

Okay so I'm 17 and my periods 4 days late, I know it could just be late but I'm freaking out a little... My parents are really strict and if I'm pregnant I don't even know how I would tell them but I know they wouldn't be supportive. I know I might not be pregnant but my nipples are sore to touch and I know that's a sign of early pregnancy. I'm not really sure what to do and I don't really have anyone to speak to. Some advice would be really nice! I'm so worried!Â