My last period was May 20th . I usually have an regular period , 28 days apart . Well i had unprotected sex on June 3rd . My period was due June 17th but it skipped . I woke up this morning with a gush of dark red brownish blood in the toilet & that was it . Now im jst spotting little by little & its dark brownish reddish . I took a pregnancy test but it said negative . Ive had symptoms of a pregnancy like back pain , tiredness , fatigue , increased appetite , & breast tenderness / enlargement . Im clueless as to what is going on . Please help !