Positive or negative?

I took a pregnancy test yesterday because my period did not come on when it was supposed to. It was supposed to come 3/15/14. I usually cramp a little the night before, but I didn't. I have no signs of it coming at all. I do not know if I am seeing an extra​ line, it looks very very faint. 
​Please tell me what you think. I will be testing again in about a week or so.