What is going on??

Amanda
So I'm a little over 2 weeks past AF being due with no signs of a period. 
I've taken 3 tests, all negative. I've had headaches here and there for the past couple weeks, a little light cramping throughout this past week but no other symptoms. 
I stopped my birth control 2 months ago so I'm not sure if this has anything to do with this. Please help! What do you guys think?