Any solution for so many days of spotting?


I have PCOS and trying to conceive.For everyone who has PCOS, dont usually have periods.For me its the opposite.I have spotting for 4-5 days every 14-18 days which leads to a 2-3 day flow. This time I spotted from for straight 8 days starting from cycle day 17 and didn't had a flow. :'(

Really frustrated and no doctor seem to be able to find out what is wrong. Currently on Metformin for five months. Does anyone else have the same issue and have found a solution? Any help will really appreciated. I feel really broken everytime the spotting starts.