Does this sounds like morning sickness?

I am late on my period but im not always regular either I have been for the last 4months and this month no AF ive been trying to get pregnant for 3yrs and no luck.... I was suposse to start on the 1st of July and I took a pregnancy test on the 3rd and it was negative... and today the 5th I woke up and I had the worse felling in my stomach ive ever felt...the Pressure was located in the middle of my abdomen not lower stomach I was so sick to my stomach and it also felt like pressure and my back hurt as well... I try-ed to throw up but nothing came up... It only lasted about 30 Min's and went away.... Im not sure what it was ive never experienced anything like it before.. I was just wondering if anyone had an idea what it could be....