Spotting or period??

I have PCOS and I have a very hard time figuring out what is just spotting and what is an actual period? I bleed so randomly and inconsistently I never know what to say when a doctor asks when my last period was so I've been trying to track my bleeding with this app but it hasn't helped my confusion at all so far.. I feel like I'm missing key information women have about being a woman or something. Anything you can think to say would likely be helpful 🙂