I'm 19 and in a serious relationship. My boyfriend and I have unprotected sex, but he never ejaculates in me. My periods are usually abnormal, but for the past 3 months it has been consistent. Well, I missed my period about a week and a half ago. When I woke up a few days ago I had brown dischage that usually happends when I end my period. There was just a little bit through out the day. I took a home pregnancy test that day and it came back negative. There is still a faint trace to nothing of this dried blood. Also the day after the discharge occur there was still some but at times it looked like it a had a bit of a red tint. What may be the cause and/or causes of this?