Prolonged bleeding. Go to doctor again.

I m mother of 9months old, after 1 month of delivery I got period, after that little bleeding for every 8 to 10 days .. I went doctor she said it's common in Brest feeding .. but 2 months back I started bleeding heavily 12 days and doctor gave me PAUSE mf bleeding didn't stops and after that gave meprate 10 mg .. starting 10 days on meprate bleeding stops and started again while taking meprate .. so I went to doctor she make ultrasound and told no problem only overies r enlarged due to cysts and gave me depo provera .. after taking depo provera bleeding stops but every day spooting is Thier... If I do yoga,went on bike, walking  spotting stars.. I don't know what to do is it any serious problem..it's been 25 days of taking depo provera some day spotting is their some day not,why this is happening.. what should I do .. is it a big problems.. should I go to doctor again.. please help me..