Talk to Gynecologist on Irregular Periods

I had my periods occurring after every 2 weeks with spotting for 3 4 days and then proper periods as a result period goes up to 10 days 3yrs back i was diagnosed with pcos at that time my periods were delayed in between i took medicine for half yr and it all improved with periods occoring sometimes kn time and delayed sometimes but this is happening to me since last 3 4 cycles and i also have mild pain in my left lower pelvic region during cycle and pain resolves with pain killer and iam getting my cycle disturbed since i got a extreme pain without my periods in that region after that i suffered this pain again during my period and then after that mild pain in again 2 period cycles plz tell me possible diagnosis