period talk need advice

I been getting my period every month now so on march 23 I was suppose to get my period which I didn't..I got it April 2,2017 which I always get cramps 3 or two days before I start my period but this time I got cramps the same day and than I started my period..I felt so tired and lazy with this period.. my period is light not heavy I don't really need to use a pad only when I have the urge to pee my period comes down.. today is my last day..and I been feeling slightly cramps which that never happens to me is this normal..What could this be