Why do i have sharp stabbing pains in my left ovary?

Patient: 2 years ago, i had a blood test done as i had irregular periods, my go told me that my results indicate that i have pcos however ultrasound showed my ovaries clean. now im getting sharp pains in my left ovary and lower back. is this related to ovarian cysts or am i ovulating?

Symptoms: Sharp stabbing pain

Doctor: