I had my last period on October 27th. I would say it lasted for about three to five days. It has been over a week since I had my period, and last week I began experiencing light cramping, such as I would have just a couple of before getting my period. Today, I have been staining a very light brown, with very, very light discharge that is a clear brown. I also saw on the toilet basin something that looked like a thin piece of red skin. My last intercourse was about a month ago, so I don't suspect it to be due to implantation. I had one home pregnancy test say I was not pregnant. What could this be?