Shorter and lighter periods than normal???

For the last 3 months my periods have been 2 or 3 days of light bleeding with no clots and very little cramping.... very unusual. They are normally 5 days of which the first 3 are painful cramps with many clots. Also my cycles have been anywhere from 24 to 35 days.. they use to be 28 days like clockwork... WTH is going on?? Anyone else dealing with this?