So my periods have consistently been coming on Tuesdays for a few months now and three weeks ago I had a very light amount of red blood on the Sunday before my period would have began. This went away Sunday night and came back Tuesday until Saturday as a very light/brown discharge kind of period. I originally thought that this could be implantation bleeding. Then on the Thursday of this strange period, I took a hpt and the results came back negative. Then this Monday I woke up completely nauseous and threw up and then had stomach cramping and pain all day. I took another hpt that night that came back negative. I have been on and off nauseous all week and should be expecting my period this coming Tuesday ( August 25 ), however, I am concerned that I could be pregnant.