possibly pregnant?

I'm 2 days late on my period I don't have much symptoms. I had back pain later in this evening, on and off headaches, nausea/feeling dizzy in the mornings, besides that a week before my scheduled period I been so tired no matter how much sleep I got I just wanted to sleep but I'm back to normal with that now. I took a pregnancy test yesterday around noon it came back negitive. do you think I might be pregnant? has anybody had any similar symptoms or none at all and still was pregnant?