Hi Trin. This is certainly something you should see your doctor about to help you manage your symptoms and possibly do some investigation. Ovulation pain is a relatively common complaint and tends to happen 'mid-cycle'. It will be hard to tell when mid-cycle is for you because you have irregular periods. Some girls have irregular periods as their 'normal' but certainly there are things that can be done for this and also to manage the pain and heaviness. I am reassured by the fact that you can do endurance exercises. Good luck!!