Help! Not knowing what's going on!

So I have been cramping since Friday Sept 1st when I was supposed to start my period. I've never started so I was 3 days late. I'm never late on my periods, like at ALL. Then on Sept 4th I started bleeding lasted till the next day which is Sept 5th. And now today I'm not bleeding at all. None what's so ever. I don't know what's going on.