Im 9 days late I am fairly regular since i

Patient: Im 9 days late. I am fairly regular since i got of the depo shot a year and a half ago. I been getting cramps like my period is coming but no site of it. Also backaches,Lightheaded, night sweats, sore throat, sensitvity of my breast on and off, and sharp chest pains. I took a pregnancy test it was negative. Could i be pregnant if not what could be the cause of this