Helpppppppp

Okay so, AF is not due till Tuesday, and today after I showered I had some pinkish/brown discharge. I don't know why. My fiancée and I have gotten jiggy with it but could it be that AF isn't coming? I took a pregnancy test and it had a faint positive. I don't want to get super excited if it's only AF, but has that happened to anyone before? It's never happened to me and my AF is usually every 14 or 15th so I'm like Gaaaaahhhh.