symptoms but negative test

Hi,

I'm experiencing symptoms and it feels like I'm pregnant... but the test was negative and nothing showed up in my blood either.
I have larger, painful, and heavy breasts.
Stomach pain like my period is about to start.
Cravings.
Emotional.
Sometimes crying over the smallest thing.
Getting irritable quickly.
I did get my "period," but it was only blood in the morning and then nothing more, and the next day it was the same, and then they stopped... I've never had this before... Does anyone have any advice? I really don't know what to think...