So you got your period, that definitely means you ovulated earlier that cycle, right? Not necessarily. Breakthrough bleeding (which is not the same as your period!) can happen when you don't ovulate. This post covers what breakthrough bleeding is and how it's different from menstruation and implantation bleeding.
Can You Get Pregnant on Your Period?
Is spotting for 4-5 days before your period normal? - Quora
What is spotting, what causes it, and when is it normal?
Can Fibroids Cause Spotting and Bleeding Between Periods?
What is Breakthrough Bleeding and When to Call Your Doctor
What Is Implantation Bleeding and When Does It Occur?