Could I be pregnant

Sarah
I had sex on February 24, I spotted on the 4th, and today, but have not had a real period. I'm never irregular, and this passed couple of days I've been extremely nauseous. I had a test done at the hospital, but it was on March 3rd not even a full two weeks after I had sex... However it came back negative.. Im very confused... And wonder if there's a chance.