Suggest Treatment For Irregular Periods

For most of my life I have very irregual periods, maybe one in the winter and then 2 in the summer, they were quite heavy and painful until after I had children. Now I am 53 and for maybe the last 3 years I have had very regular periods, I started timing them and they are coming every 27 days but are quite light. This seems the wrong way round as at my age I should be expecting less periods not more.