Every month its became a pattern that I get my period 5 days to a week earlier than I am supposed to according to <a href="https://play.google.com/store/apps/details?id=com.glow.android.eve">Eve</a>.. I was once starting my period every month around the 21st but now I’ve made it all the way to January 2nd just by having these week early periods. Should I be worried about this? What could be causing it?