u/Background_Fun_3453

Is it normal for periods to start days later or earlier than when the tracker app says it should? I got the my calendar app 2 years ago to help track my period so I dont have any accidents and so I dont waste pads when im feeling phantom periods. But the tracking doesn't seem helpful when im 2 days early or even 6 days late from when the calendar is saying I should start. And it's every month. Is this normal? Should I get a better app?

So from what I can remember it's about a high school girl who learns about this other girl that is going to off herself the night of a school dance and main character can travel back in time to stop her, but when she stops the girl I think a bomb goes off at the dance? So she has to figure out who planted the bomb and how to save both the girl and the school.