Pregnant?

I had sex June 6. The day after my period ended. I am not on birth control and my partner didn't wear a condom, but pulled out. About 5 days ago I have lost my appetite completely, smells make me sick to my stomach and the only thing I seem to be able to eat are bananas. I am three days late and my pregnancy test came out negative. I am nauseous all day every day, but don't vomit. Last year I was 8 weeks pregnant with 4 negative pregnancy tests. Could I be pregnant?