No-Period

I got the shot about a month ago, and I was told that some people will still get their periods and some wont, i havent gotten mine and when i got the shot it stopped my period within like 24 hours.. This is when i would normally get my period, yet i havent gotten it, but i am still having a few of the period symptoms such as a stomach ache and a little cramping.. Is this normal? is it normal to get some of the side effects of a a period, when you dont get a period due to Depro Provera?