What's the difference between really upset vs. Stressed?

Rachel

I cried at a negative result 3 days before period. For like a half hour. I mean I was really bummed I wasn't pregnant, but I don't think it qualifies as such stress to delay my period. I'm now three days late.

How do you know if it's your body being stressed because you're so upset vs. Just normal upset and no real high amount of stress?

Does that make sense?