My sister says that her moods plummet a week before her period. She told me that her period will start soon because she noticed a strong craving for sweets. I am not sure when mine starts because my moods go everywhere any ways. I suspect that one week before would be about right. But, sometimes I think it is going to start and my period just waits a while. ( I once stressed my way out of a period. I was like "Eh, I didn't have a period this month."
Nurse: Would you like to take a pregnancy test.
Me: No. I can't be pregnant.
This went on for a few more cycles before she gave up and suggested that I might just be stressing out. I started right in the middle of a lab test at college. So, I don't exactly have predictable period times.