Noticed Dark Brown Discharge Like Clots After Getting Off BCPS

I was on bcps for about 8 years non stop. I decided to get off of them in March of this year. Upon getting off of them, I would go from not having my period at all to having brown discharge. In June, I had brown discharge for about a month and pass several clots, including one that was very, very large. I went to my doctor and had a abdominal and TV sonogram all with normal results(Paps came back normal as well). For the past few months I have had on and off brown discharge and light bleeding to regular amounts of bleeding for about two weeks at a time (sometimes it will stop all together and come back a few days later) I'm very confused and nervous. Please help.