Hi. I'm 19 . I started my period September 6 and was 12 days late . just started bleeding yesterday . I am really worried . before I started bleeding I took a test and it came up positive with a faint line . went to Dr and sane thing . took a test yesterday again and positive with a faint line . last night I had really bad cramps and blood was kind of dark but lighter blood stream then regular period and no cloths . this morning my test came back negative what do you guys think ?