Am I crazy?

Ok so almost a week before Christmas I took a test before leaving town and it looked negative. I put it back in the box and left town. I haven't had my af since nov 16th. So on Christmas day I took another test and it showed a faint positive. Yesterday I took a digital and it was negative. Then this morning I took another digital and it was also negative. When I went to put it back in the box I noticed that the test I took before I left was also positive. I'm so confused...any advice?