Period is usually late, but all of a sudden early?!

Alexandra • 28 years old. Proud mother of 2! Living life with my little family: my husband, our daughter, our newborn son, and our sweet kitty 👨‍👩‍👧‍👦🐱 Enjoying every moment with my little one ❤️ Endo, Adeno, PCOS warrior

My period is usually really late, arriving between day 35-42 typically, and all of a sudden I think it just started, but I’m only on day 26 of my cycle. I have PCOS which explains my late periods, but I NEVER get early periods. Any explanation?