What Causes Dark Spots On Back, Face And Chest To Go Dark During Menses?

Hi.. I am having dark spots on back, on face, on chest. They go darker during my periods. And also i have Polysicticovariansyndrom. But i got cheked up with Gynocologist. She said i only have 2 cysts so its not a big problem. But my skin looks different with increasing black spots like flat moles, discoloration on my chin. can you tell me whats going on?