I have been having a feeling like im going to start my period but nothing comes out. Maybe a little Discharge that is dark brown. but no red blood. I have had unprotected sex. the week that i was due for my shot and the week after. Could i be Pregnant. I been feeling a little tired. my breast are a little swollen and i am constipated. and have a little gas. Slight raise in temp. 99.2 all day. any thoughts.