Late period, but not prego

My period is late 10 days, but I'm not pregnant? I read that being stressed could delay it but I'm not really stressed. I'm curious to why this is happening. I have small cramps like it's going to start and I'm emotional and snacky. I have a lot of white discharge that's clear, but I was told that's normal. Should I even go to doctor or should I want until the end of this month? I'm 20 years old, so it's kinda scaring me