hi, I am 17 years old and I am concerned I might be pregnant. My period was about 5 days late, I took a pregnancy test which read negative, and then 2 days later received what I thought was my period. But the bleeding only lasted 2 days, and the blood wasn t red. It was this thick, black-brown liquid, and there was not very much of it . I am now very lightly spotting. I have had severe mood swings as well as being exhausted despite full nights of sleep over the past two weeks.