Yes, no, maybe so?

Could I be pregnant? I took a test on the first and it said negative. I was supposed to start my period on the 3rd and still nothing. I don't even have signs that I am supposed to start. Like usually my face breaks out or I spot or I cramp. I started feeling sick to my stomach yesterday and again this morning but I didn't vomit or anything. Is it too soon to know?  Could it be possible or is my mind playing tricks on me?