Confused and need insight

Heather
Last period I remember having is April 7-12 
I don't remember exactly when I started in March 
Long story short 
It's June 12 and I haven't had my June period 
I took a test two days ago and it was negative 
I have had a lot cramps thinking it was my period 
They are off and on 
My cramps are isolated in my back just like they normally would when my period is about to come 
Yet still no period 
Any advice