Not sure what's going on...

A full week before my period I was nauseous. I'm still really sensitive to certain smells. My period was a day late. I took 2 pregnancy test both came up negative. I only took then because I had unprotected sex during my fertile window. My period started the next day and hasn't ended. It's on day 5 and it always ends after 3. I'm not sure what's going on.