Missing period, spotting? Have you experienced this?

When I was 19 a Fertility Specialist diagnosed me with PCOS due to having pretty much non existing periods, Blood tests revealed I had high estrogen and high testosterone while everything else was normal range. Back in July my Doc prescribed me Metformin 1500mg for a month to see if my period came, when it didnt he prescribed me clomid 50mg in mixture. I induced my period in August with provera before taking the clomid. Sept I had a period on CD 33, again in Oct on CD 33, In Nov period came on CD 38, In Dec it came on CD 33 and in Jan my doc upped the dosage to 100mg of clomid and I completely missed. In Feb I started spotting brown for a week, it turned red/brown and has lasted over a month non stop, still no period. Had pg test and blood test done last month and revealed negative for pregnancy. How could this be? How could I miss my period when I had one every month on 50mg. It should have worked better right? I stopped taking my metformin around the time I started spotting, could that be the reason why? I never took my last dose of Clomid because I never started my period so I dont even know if its worth taking anymore. Whats your opinion? Have you experieced this?