Hey, I missed my period. I had intercourse August 8th, 2014. I spotted recently but it wasn t a period. I had cramps & lower back pain. Now as of Sep. 21St 2014 I have pressure on my lower left side of my abdomin. When I laugh, cough,& sometimes move I can feel the pressure. I dont have nausea or sore breast but I took a pregnancy test. It was negative but with no period & these symptoms... what could it be? Please help.