still no period iam at a loss

I have normal periods ever since I got of depo back in Jan 2016 normal my cycles run between 24-27 day cycles. and for the past two month the have come on 24 day cycles. I had no bleeding and no spotting . I take so many tests that were negative and had a blood test done today and the results were negative as well . my first day of my last period was may 13th ... still at loss why nothing is showing up I have never had missed a period and they come at every month... any ideas ?