For the past few months ive been getting shorter time between periods, around 2-3 weeks. (Heavy periods lasting 5-7 days)

I haven't thought that much about it but I'm starting to overthink things as per usual.

I'm 16 and have had my period for at least 3/4 years.

I always expect the worst so im thinking like early menopause, disease whatever, idk googling things are probably the worst thing for me to do right now haha.

Thinking it could be stress or something, but im always stressed so idk.

If anyone has any advice or possible explanations that would be great thanks :))

Also how do you change the calendar so it predicts my period at the right time, because for the past few months its been predicting a week late, and i dont remember how to change the settings