What Makes My Stomach Bloated And Causes Weight Gain?

I had my surgical abortion done on 11th November 2011.I did not bleed thereafter.I went for a checkup after 20 days post my abortion since there was slight discomfort in my lower abdomen eversince.I was diagnised of a cyst in my left ovary.Thereafter the doctor prescribed me duphaston to get my periods.I still have not got them.Also I feel a bloat in my stomach and feel that I have gained weight in these months.What could possibly be the reason??