I've pco and had cyst surgery 2 yrs back, now i get regular menses but from 4th day of menses i get chocolate coloured blood.is it endometriousis?

Endometriosis: Most common symptom of endometriosis is painful periods. If you have pain all throughout your cycle, you might have endometriosis. You probably have heard of "chocolate cysts" with endo. These are cysts inside your pelvis that are endometrial tissue. They are dark brown from bleeding with your cycle. The blood you are having is something completely separate. Pcos and endo are also separate.