What Causes Delayed And Prolonged Period While Suffering From PCOS And Hypothyroidism?

Halo doctor, I m 29 years old and suffering from pcos and hypothyroidism. I have very irregular periods. This time my period came after 3 months. Its been 16 days and the bleeding still hasn t stopped. There is mostly discharge of bright red blood tat looks like it came from a fresh cut. I also have slight pain in my lower abdomen. What do u think is wrong?? And should I see a doctor?? Thanks so much in advance.