Negative pregnancy test, missed period!!! Ugh!

Marissa
I'm never ever late. I was supposed to get my period yesterday and nothing.. Nothing today.. I have been feeling very nauseous the past week! I took pregnancy test three days ago, just because.. Negative. Took one yesterday, negative. Took one this morning.. Negative! Ugh. I'm so confused because my period never comes late, ever!! I know it's only a day but this has never happened! I always come day of or day early. I don't know what to think.